it is not the purpose of this planning document to replace any product and tools' operating manual/instruction.2 General Radio Network Planning Process
The flow diagram below shows one of the more common work procedures recommended by the Radio network planning team. It covers all the major area that requires technical attention from the conceptual beginning of a network design to the provisioning of final network parameters required for the deployment phases. most of the content provided in this planning guide can be applied to LTE system design with field implementation considerations.
1
. Although there are numerous and detailed references made to particular tools.1 Introduction
The purpose of this document is to provide systems engineers/planners with a set of guidelines and introductions to LTE deployment planning that may aid the design of a high quality Long Term Evolution (LTE) RF System. In general. Please refer to the official publications of the respective product/tool for their most up to date functionality.
1.1 How to Use This Guide
1. Specific RF planning information unique to Huawei’s LTE EUTRAN product is also provided.

Table 1-1 Quick Guide
Chapter # 1 2 Chapter Title How to Use this Guide LTE Fundamentals & Key Technologies Frequency and Spectrum Planning Link Budget and Coverage Planning Interference. Overview of LTE capacity planning as well as highlight all the critical factors and considerations that will affect capacity for an LTE network. ACLR. Learn definition of different parameters such as equipment parameters. engineering parameters.1. Understand some basic concept for interference analyze such as ACS. traffic model parameters. etc. Overview of LTE Spectrum definition as in 3GPP. some key LTE technologies such as MIMO and FFR will be presented in this section. Learn different interference between two different systems among serials TDD and FDD system.
3
4
5
6
7
8
9
2
. Learn about some of the basic propagation models as well as critical features that affect link budget values. Meanwhile. Guard band and Refarming Analysis LTE Access Network Capacity Planning U-Net Simulation and Operation LTE Network Key Performance Indicators Network Planning Checklist Detailed Description Understand the contents of this document. Understand U-Net operations. Provide LTE KPIs classification and KPI Acceptance Procedure Provide a list of items that Planning engineers need to consider and ideally have answers from customer before performing any detail planning. High level view on how to predict and simulate based on U-Net. Understanding the various reuse options available to LTE as well as band selection and combination overview Understand the parameters that comprise the LTE RF Link Budget. Learn LTE fundamental which includes PHY and MAC layer technology. etc.3 Quick Guide to Content of Each Section
The LTE RF Planning Guide is a collection of fairly independent chapters covering various aspects of LTE system RF design and implementation. The table below outlines the key features of each Chapter.

It can be straightforwardly extended to a multi-access scheme called OFDMA. I. where each user is assigned a different set of subcarriers.
2.1 OFDM Fundamental
OFDM was selected for the downlink because it can • Improved spectral efficiency • Reduce ISI effect by multipath • Provide better Protection against frequency selective fading OFDM is a scheme that offers good resistance to multipath and is now widely recognized as the method of choice for mitigating multipath for broadband wireless.3.
5
. Frequency Spectral Efficiency Improvement OFDM increases spectral efficiency by incorporating multiple carriers in the same frequency space as a single carrier.Figure below is the LTE uplink allocation structure from a time and frequency perspective.

Reducing the Impact by Inter Symbol Interference (ISI) Improvement of frequency spectral efficiency requires the reduction of Inter symbol interference (ISI). it will also be much easier to implement scheduling algorithm based on Frequency Selective Scheduling to improve system throughput in the manner shown below.
III. the frequency coherence bandwidth is much smaller than 3G systems while and correlation factor is much higher. This is achieved by tighter frequency roll off and alignment of nulls and peaks between different frequencies. Better Protection Against Frequency Fading Smaller subcarrier and resource block bandwidth increase robustness against frequency related fading
With this smaller carrier bandwidth.
6
. As a result.II.

which benefits the mobile users in terms of battery life and power efficiency.2 SC-FDMA Fundamental
Single Carrier-FDMA is a recently developed single carrier multiple access technique which has similar structure and performance to OFDMA.3. OFDM signals have a higher peak-to-average ratio (PAR)—often called a peak-to-average power ratio (PAPR)—than single-carrier signals do. hence also known as DFT-pre-coded OFDMA or DFT-spread OFDMA. a multicarrier signal is the sum of many narrowband signals. The reason is that in the time domain. this sum is large and at other times is small. At some time instances. One prominent advantage of SC-FDMA over OFDMA is the lower PAPR (peak-to-average power ratio) of the transmit waveform for loworder modulations like QPSK and BPSK. which means that the peak value of
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.Frequency Selective Fading Resistance
2. SC-FDMA can be viewed as a special OFDMA system with the user’s signal pre-encoded by discrete Fourier transform (DFT).

whereas in downlink each subcarrier only carries information related to one specific modulation symbol. Main differences between the two modes are • Frame 0 and frame 5 (always downlink in TDD) • Frame 1 and frame 6 is always used as for synchronization in TDD • Frame allocation for Uplink and Downlink is settable in TDD
The sampling rate in both FDD and TDD is the same and both technologies operate under a 1-ms sub-frame (TTITransmission Time Interval) and 0. The figure below shows the relationship between OFDM and SC-FDMA in LTE. The major difference between the downlink and uplink transmission scheme is that each subcarrier in the uplink carries information about each transmitted modulation symbol as shown in figure below.
2. because it reduces the efficiency and hence increases the cost of the RF power amplifier. This high PAR is one of the most important implementation challenges that face OFDM. The first 3 configurations (0-2) for TDD can also be viewed as 5ms allocation due to repetition. which is one of the most expensive components in the radio. As a result. The figure below shows a detailed relationship between rates and frame structure.
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.4 LTE Frame Structure
The figure below shows the frame structure for LTE under Time division mode (TDD) Type 2 and Frequency Division mode (FDD) Type 1. the uplink power level due to SC-FDMA also need to be increased by 2~3dB to compensate for the extra noise due to more spreading.5us timeslot definition.the signal is substantially larger than the average value.

Resource element is the smallest unit of resource assignment and its relationship to resource block is shown as below from both a timing and frequency perspective.5 LTE Resource Block Architecture
The building block of LTE is a physical resource block (PRB) and all of the allocation of physical resource blocks (PRBs) is handled by a scheduling function at the 3GPP base station (eNodeB).2. In summary.5ms in time domain and each 0.
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. • One resource block is 0.5ms assignment can contain N resource blocks [6 < N < 110] depending on the bandwidth allocation and resource availability. • There are 7 symbols (normal cyclic prefix) per time slot in the time domain or 6 symbols in long cyclic prefix.5ms and contains 12 subcarriers for each OFDM symbol in frequency domain. • One frame is 10ms and it consists of 10 sub-frames • One subframe is 1ms and contains 2 slots • One slot is 0.

2. The figure below shows the locations of the reference signal within each sub-frame when transmit antennae are used by the cell.
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.6 Reference Signal Structure
Reference signal is the “UMTS Pilot” equivalent and it is used by UE to predict the likely coverage condition on offer for each of the eNodeB cell received.

due to channel reciprocity.As LTE is a MIMO based technology. the eNodeB can then use the UL channel as an estimate of the DL channel.
2.7 Timing and Sampling Architecture
Sampling frequency varies under different bandwidth configuration in LTE and the table below summarizes the possible combinations. the channel-sounding mechanism involves the UE’s transmitting a deterministic signal that can be used by the eNodeB to estimate the UL channel from the UE. As defined in the standard for TDD operations. different antennae will be transmitting reference signal at different time and frequency and how these are allocated are shown below. If the UL and DL channels are properly calibrated.
A quick summary of all the physical layer information for LTE is shown below. it can have more than two transmit antennae and in order to avoid reference signals from the same cell interfering with each other.
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.

to form a cyclic prefix (CP). causing interference to neighboring users. The “wasted” power has increased importance in an interference-limited wireless system. the delay of each path should not exceed the guard interval where the number of waveforms within the integral time of the FFT is an integer
The cyclic prefix. In order for the IFFT/FFT to create an ISI-free channel. It comes with both a bandwidth and power penalty. although elegant and simple. the channel must appear to provide a circular convolution. In summary. an additional symbol must be counted against the transmit-power budget. the use of the cyclic prefix entails data rate and power losses.7. which has low complexity. Adding cyclic prefix to the transmitted signal to create a signal that appears to be just like circular convolution and this is done by copying the last part of each OFDM symbol to the front of each symbol with the length of a guard interval.
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. the cyclic prefix carries a power penalty of v dB in addition to the bandwidth penalty.1 Normal and Extended Cyclic Prefix
The key to making OFDM realizable in practice is the use of the FFT algorithm. the required bandwidth for OFDM also increases. Also. Since redundant symbols are sent.2. to prevent the guard interval from destroying the inter-sub-carrier orthogonality. is not entirely free. Similarly. Hence.

The figure below shows the location of PSS and SSS in LTE-TDD and the major difference from LTE FDD is that LTE TDD embedding the Primary Sync channel in the DwPTS so the location will not be affected by different DL/UL combination ratio
2. due to large cell radius.2 Synchronization Channel
The diagram below shows the relative position of Primary Synchronization (PSS) and Secondary Synchronization (SSS) within the radio frame in a FDD LTE system. an extended CP option can be used. e.
2.Where L is the power used for non CP transmission. One uplink Slot is as below.7.8 Uplink Physical Channel Structure
It is worth mentioning the physical structure of uplink channel. In the case where there is a large delay spread.
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.g.

8. Sounding and Demodulation Reference Signal Structure
The figure below shows the relative position of uplink control channels in the frequency domain in relation to the entire channel bandwidth.2. 1) PUCCH resources are located at the edges of the spectrum • To maximize frequency diversity 2) Multiple UEs can share the same PUCCH resource block 3) PUCCH is never transmitted simultaneously with PUSCH from the same UE 4) Two consecutive PUCCH slots in Time-Frequency Hopping at the slot boundary
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. In summary.1 FDD Uplink Control.

2.9 Multiple Input Multiple Output (MIMO)
MIMO and other transmit spatial diversity scheme is a newer application than receive diversity and has become widely implemented only in the early 2000s. Multiple antennae transmit schemes—both transmit diversity and spatial multiplexing—are often categorized as either open loop or closed loop. the incremental cost of using them for transmit diversity is very low.The Figure below shows respective position of the uplink demodulation reference signal in FDD LTE uplink frame structure including sounding reference signal position.1 3GPP MIMO Mode Definition
The table below shows the 8 definition used by 3GPP for MIMO modes
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.9. A high level signal processing diagram is shown below. processing is required at both the transmitter and the receiver in order to achieve gain while removing or at least attenuating the spatial interference. if the multiple antennae are already at the base station for uplink receive diversity. it uses UpPTS sub-frame. Additionally. By using multiple antenna to transmit multiple path of information to UEs. As the signals sent from different transmit antennas interfere with one another. SRSs can be transmitted in an ordinary sub-frame or in UpPTS sub-frame to improve spectral efficiency. Normally. open and closed loop.
2. In general there are two mode of MIMO. either better throughput or lower SINR requirement can be achieved and the frequency selective characteristics of LTE is perfect for the implementation of such technologies.
For LTE TDD only.

2. As a result.9.2 Open Loop MIMO
Open-loop systems do not require knowledge of the channel at the transmitter.
The figure below shows a possible N Antennae + M input layers setup in spatial multiplexing
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. open loop operations occur when the access network does not have information or feedback from the UE to do coding adjustment or signal is not good enough.

As a result.
As a result. closed-loop systems require channel knowledge at the transmitter. The figure below shows a functional view of closed loop MIMO.3 Closed Loop MIMO
On the contrary.2. Hence. thus necessitating either channel reciprocity—same uplink and downlink channel. possible in TDD—or more commonly a feedback channel from the receiver to the transmitter. closed loop operations occur when the access network execute dynamic adjustment based on feedback from the UE. a more accurate coding application can be applied to the communication with the UE. unlike open loop. The figure below shows where the pre-coding function may exist in a N Antennae with M input layers
In mode 5 (Multi-user MIMO).
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. the overall throughput per cell is increased. different UEs are receiving downlink data from different antenna.9.

If the receiver also has multiple antennas. the capacity still grows approximately linearly with since capacity is linear with SINR in the low-SINR regime. unlike transmit diversity and beam-forming. Even two appropriately spaced antennas appear to be sufficient to eliminate most deep fades. The cost of each additional antenna. Although capacity gain is much smaller than at high SINR. Spatial Multiplexing Matrix Using Two Antenna Ports with Cell-Specific Reference Signals Spatial multiplexing is where multiple independent streams are transmitted across multiple antennas. When the SNR is high. when the SINR is low. The following is a quick summary of some possible pre-coding matrix combination under different scenarios I.9. grows as when the SINR is large. Instead of increasing diversity. multiple antennas in this case are used to increase the data rate or capacity of the system. or maximum data rate. which paints a promising picture for the potential benefits of spatial diversity. and the associated signal processing required to modulate or demodulate multiple spatial streams may not be negligible. the capacity of the system can theoretically be increased linearly with the number of antennas when performing spatial multiplexing. spatial multiplexing works mainly under good SINR conditions. LTE can still support spatial multiplexing by coding across multiple users in the uplink. its RF chain. the streams can be separated out using spatial multiplexing. the capacity maximizing strategy is to send a single stream of data. On the other hand. The matrix used for two antennae spatial multiplexing is shown below. but this trade-off is often very attractive for a small number of antennas.
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. spatial multiplexing is optimal.4 Pre-coding Matrix
3GPP 36-211 defines the types of matrix need to be used when multiple antennae are to be used for different conditions. If the mobile station has only one antenna. This is called Multi-User MIMO (MU-MIMO).2. One main advantage of spatial diversity relative to time and frequency diversity is that no additional bandwidth or power is needed in order to take advantage of spatial diversity. However. using diversity pre-coding. In a rich multipath environment. A 2 × 2 MIMO system doubles the peak throughput capability of LTE but this is unlikely to be possible for all users in the cell due to variation in SINR.The capacity.

Spatial Multiplexing Matrix Using Four Antenna Ports with Cell-Specific Reference Signals
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.
III.II. Transmit Diversity Matrix Using Two Antenna Ports The following matrix applies to input x is and y is the resulting output using a two antenna output configuration.

To perform transmit beamforming.5 Beam Forming
Multiple antennas in LTE may also be used to transmit the same signal appropriately weighted for each antenna element such that the effect is to focus the transmitted beam in the direction of the receiver and away from interference. beam forming is specific only to LTE TDD and can operate either under 4x4 or 8x2 configurations.IV. capacity. the transmitter needs to have accurate knowledge of the channel. Beamforming can provide significant improvement in the coverage range.
2.
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. thereby improving the received SINR. Transmit Diversity Matrix Using Four Antenna Ports The following matrix applies to input x is and y is the resulting output under a four antenna output configuration. As of today. which in the case of TDD is easily available owing to channel reciprocity but for FDD requires a feedback channel to learn the channel characteristics so it is not implemented in LTE Release 8 or 9 yet.9. and reliability. The beam-forming weight vector should increase the antenna gain in the direction of the desired user while simultaneously minimizing the gain in the directions of interferers.

2. it is not possible to associate a discrete AOA with a signal impinging the antenna array. The DOA-based beam-former in this case is often called the null-steering beam-former. Each DOA can be estimated by using EUTRAN signal-processing techniques as requested in 3GPP-TS 36-214.
21
. Thus far. Typically. from other users or from multipath reflections.10 LTE FDD vs LTE TDD Main Features Comparison
The following table summarizes the major similarity between LTE FDD and LTE TDD
The table below summarizes the difference between the two technologies. the DOA based beam-former is viable only in LOS environments or in environments with limited local scattering around the transmitter. The null-steering beam-former can be designed to completely cancel out interfering signals only if the number of such signals is strictly less than the number of antenna elements. we have assumed that the array response vectors of different users with corresponding AOAs are known. Ideally. a beam-former extracts a weighting vector for the antenna elements and uses it to transmit or receive the desired signal of a specific user while suppressing the undesired interference signals. In this case. there exists a trade-off between interference null and desired gain lost. In practice. Therefore. From these acquired DOAs.One popular beam-forming algorithm is based on Direction of Arrival where the incoming signals to a receiver may consist of desired energy and interference energy—for example. The various signals can be characterized in terms of the DOA or the angle of arrival (AOA) of each received signal. each resolvable multipath is likely to comprise several unresolved components coming from significantly different angles. the beam-former has unity gain for the desired user and two nulls at the directions of two interferers and can place nulls in the directions of interferers.

2 UE Procedure for Reporting Channel Quality Indication (CQI).12. PMI. A UE shall transmit periodic CQI/PMI. For transmit diversity RI is equal to one. A UE shall transmit periodic CQI/PMI or RI reporting on PUSCH as defined hereafter in sub-frames with PUSCH allocation. where the UE shall use the same PUCCH-based periodic CQI/PMI or RI reporting format on PUSCH. otherwise. For a-periodic CQI reporting. and RI reporting on PUSCH if the conditions specified hereafter are met. RI reporting is transmitted only if configured CQI/PMI/RI feedback type supports RI reporting. it is configured without PMI/RI reporting. the UE shall determine a RI corresponding to the number of useful transmission layers. the time and frequency resources that can be used by the UE to report CQI. Precoding Matrix Indicator (PMI) and Rank Indication (RI)
As stated in TS 36-213. A UE shall transmit a-periodic CQI/PMI. or RI reporting on PUCCH as defined hereafter in sub-frames with no PUSCH allocation. A UE in transmission mode 8 is configured with PMI/RI reporting if the parameter PMI-RI-Report is configured by higher layer signaling. and RI reporting is periodic or a-periodic.2. CQI. Figure below shows which channels will be used for different CQI reporting scenario
26
. and RI are controlled by the eNodeB. For spatial multiplexing. PMI.

3.104-860 Table 5.1 Frequency Spectrum Overview .TDD
3GPP Release 8/9 (3GPP TS36.4.3 LTE Frequency and Spectrum Planning
3.2 Frequency Spectrum Overview . The table below shows the actual frequency range listed per the specification for the Frequency Division Duplex (FDD) version.104-860 Table 5. AWS (Band 4) and 700MHz (Band 12) while momentum is being built up also for 1800MHz (Band 3) as well as Public Safety spectrum (Band 14) According to 3GPP TS 36.5-1 E-UTRA frequency bands) has also defined the operating frequency for Time Division Duplex (TDD) based LTE technology in various frequency bands in order to operate in different parts of the world.
Figure 3-1 LTE FDD Spectrum Allocation The most popular commercial LTE bands are 2.FDD
3rd Generation Partnership Project (3GPP) Release 8/9 (3GPP TS36.6GHz (Band 7). The table below shows the actual frequency range listed per the specification for the TDD version.104 V9.0 (2010-06). Band 6 is no longer applicable and Band 15 and Band 16 are listed as Reserved.5-1 E-UTRA frequency bands) has clearly defined LTE as a system that can operate in various frequency bands into order to suit the need of different operators in the world.
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.

there is a significant frequency spectrum overlap (100MHz) between LTE TDD with WiMAX. To many WiMAX operators currently in this frequency band. i. it is an ideal opportunity to evolve their network back into the mainstream LTE technologies. Operators can assign different channel bandwidth to suit their particular needs per the figure below. at FC +/.BWChannel /2.
31
.
3.
Figure 3-3 Transmission bandwidth configuration NRB in E-UTRA channel bandwidths
The channel edges are defined as the lowest and highest frequencies of the carrier separated by the channel bandwidth.3 Channel Bandwidth and Subcarrier Allocation
According to 3GPP specification.Figure 3-2 LTE TDD Spectrum Allocation
It is worth noting that around the 2.e. The number of RB supported for each bandwidth is equal to number of sub-carriers divided by 12.3GHz band (Band 40).

1 Channel Spacing
The spacing between carriers will depend on the deployment scenario. The nominal channel spacing between two adjacent E-UTRA carriers is defined as following: Nominal Channel spacing = (BWChannel(1) + BWChannel(2))/2 where BWChannel(1) and BWChannel(2) are the channel bandwidths of the two respective E-UTRA carriers.4 Channel Arrangement
According to 3GPP specification.4.Figure 3-4 Definition of Channel Bandwidth and Transmission Bandwidth Configuration for one E-UTRA carrier
Figure 3-5 Visualizing the Relationship between Channel Bandwidth. NRB and Transmission Bandwidth Configuration
3.
3. which means that the carrier centre frequency must be an integer multiple of 100 kHz. the size of the frequency block available and the channel bandwidths. operators can assign different channel bandwidth to suit their particular needs per the table below.
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.4.2 Channel Raster
The channel raster is 100 kHz for all bands.
3. The channel spacing can be adjusted to optimize performance in a particular deployment scenario.

the interference level between sectors can be reduced. As a result. also known as the primary band. For those users location near the center of the cell. to serve the cell edge users.Advantage • High spectral efficiency and high throughput per site. each sector will only use one of the sub-sections. also known as the secondary band. will be used to serve these users. which is the remaining “2/3” of the carrier bandwidth. • No special scheduling algorithm required Disadvantage • High level of interference especially on cell edge area • Low throughput on cell boundary and lower QoS/QoE for users on boundary area. • Easy to deploy. the other 2 sections. The figure below depicts the actual layout
Figure 3-9 SFR 1*3*1 Downlink frequency planning scheme
35
. Both FDD and TDD can use this interference reduction method. thereby enhancing the throughput of those users. which “1/3” of the entire carrier bandwidth. The SFR concept is based on dividing the entire LTE carrier bandwidth into 3 sub-sections as shown below
Figure 3-8 SFR 1*3*1 Downlink frequency division scheme Under this configuration. • Coverage control of cells becomes an important factor in achieving a high throughput level
3.5.2 SFR 1*3*1 – Downlink and Uplink
SFR (Soft Frequency reuse) is the recommended frequency reuse methodology.

for TDD to work properly. GP and UpPTS).
3. Besides. the coexistence of WiMAX within the same TDD spectrum is also very common and this has further complicated the carrier and bandwidth planning for LTE TDD network from a carrier planning perspective. Moreover. the selection of carrier bandwidth for multiple carrier condition is also more complex in TDD than FDD. Failure to include enough separation will create a lot of co-channel interference which will degrade the throughput performance significantly
Figure 3-10 Uplink-Downlink Pilot Time Slot and Guard band Configuration Schemes
Lastly. carrier bandwidth. IEEE 1588v2 implementation is recommended and will help to ensure the integrity of time synchronization within the LTE TDD network. all cells must be operating in time synchronous mode to avoid any extra interference being introduced to the network. co-frequency and time sharing nature between uplink and downlink in TDD also require careful selection of guard band and pilot time slot (DwPTS. • Best results will require the introduction of Inter Cell Interference Coordination (ICIC) Advantage • Reduce inter-cell interference under a high site density deployment.
36
.Application scenario • Recommended configuration to satisfy high traffic and high site density requirement.3 TDD Specific Frequency Planning Considerations
It is very common for telecom Operators within the TDD band of LTE have a wider unpaired spectrum than the bandwidth defined maximum carrier bandwidth of 20MHz. As a result. • Improve cell edge user throughput and quality of experience.5. Planning engineers need to take all these variations along with customer throughput and coverage requirement into account when it comes to TDD frequency planning.

Results shown below are typical comparison in coverage radius between different frequency bands.5. feeder loss. cell edge user throughput and penetration loss are all dependent on the operating frequency chosen. it is important to remember many components on the radio path will have slightly different properties at different frequency bands which will modify the final cell coverage radius.4 Frequency Band Selection
As many Operators worldwide possess spectrum in various frequency bands. For example.Figure 3-11 Synchronization Solution based on IPclk or 1588v2
3. choosing which band to use for LTE is always an important consideration. However. Parameters that will affect the overall cell coverage will be discussed in the next chapter. power amplifier output. Final results are highly dependent on the actual parameters used for customer design. propagation characteristics.
Cell Range in Uplink Case -. antenna gain.Result
Figure 3-12 Cell Coverage Comparison (UL@128kbps) between various frequency bands
37
.

Cell Range in Downlink Case -. it will impact the actual cell range that can be served from a logical and signal processing perspective. a bigger cyclic prefix is configured per cell to allow a bigger delay in propagation.g. 7 symbols configuration (norma lCP) against 6 symbols (long CP configuration)
Figure 3-14 Cyclic Prefix Comparison
3. This is also known as long CP.5.5. By carrying a smaller number of symbols (6). It is highly dependent on what the Operator already owned and what is their future business plan. The figure below shows the difference in symbol configurations between the normal. LTE is more likely the technology of choice for most Operators looking at launching data services in the higher
38
. Typically.5 Cyclic Prefix Planning
Although Cyclic Prefix is not directly related to frequency or spectrum allocation. higher frequency bands are likely to deploy more data centric services for high density area (e. CBD).6 Placing Multiple Technologies@Multiple Frequency Band
Choosing which technologies for which spectrum is a major challenge for many Operators worldwide.Result
Figure 3-13 Cell Coverage Comparison (DL@1024kbps) between various frequency bands
3. As a result.

The figure below just some 1 example of what customer may do with multiple technologies and their evolution in different frequency band. better user experience. UMTS and LTE • It can remarkably reduce operational cost and improve efficiency.
39
.frequency band.
Dual-band Network Deployment is a trend
Figure 3-15 Example of Multiple Technologies Deployment to Various Frequency Band
SingleSON Solution Benefits: • SingleSON brings synergized automation for GSM. It is the responsibility of the radio planner and account managers to work with customer to determine the best combination to meet their interest.

4 Link Budget and Coverage Planning
Operators are rightfully focused on the service quality of a system and coverage is an important part of the service quality of a system. capacity. and cost so none of these can be considered in isolation. The aim of radio network planning is to balance coverage. will provide site deployment specific simulation analysis to obtain the number of required base stations in the target area. Coverage and design requirement must be analyzed in choosing parameters within the following parameter groups: • Propagation-related • Equipment-related • LTE-specific • System Reliability • Specific Considerations Achievable cell radius can be derived from the Excel based link budget tools. Various factors must be considered during LTE system coverage planning and setting of these parameters will affect coverage radius and the quantity of base stations. quality. The coverage area offered by a 3 sector and Omni site along with coverage planning flow is shown below
Figure 4-1 Radio network coverage pre-planning flow
40
. GENEX U-net. Network planning tool.

body loss. such as the pilot power boosting gain. interference margin. such as the penetration loss. receiver sensitivity. System simulation will be described in Chapter7.
41
. such as slow fading margin • Specific features that will affect the final path gain The figure below shows factors that will affect the link budget calculation process.This chapter will focus on the RF link budget itself and radio transmission model. and antenna gain • LTE-specific parameters. such as the transmit power.
4. and the interference margin of radio links to calculate all gains and losses that will affect the final cell coverage • To estimate the maximum link loss allowed based on the maximum transmit power of the terminal and eNodeB transmit power allocation. and background noise • Equipment dependent parameters.1 Conventional Link Budget
The purpose of link budget in LTE network planning is: • To use such factors as building penetration loss. Link budget parameters are grouped as follows: • Propagation (Transmission) related parameters. edge coverage rate. feeder loss. The radius can be used in subsequent design. repeated coding gain. antenna gain. feeder loss. and fast fading margin • System reliability parameters. Multiple Input Multiple Output (MIMO) gain. Coverage radius of a base station can be obtained according to the maximum link loss allowance under a certain propagation model.

and the terminal motion speed of the channel. ETU60.Figure 4-2 Link budget model – Downlink and Uplink
4. you must set the propagation parameters to be the same values. EVA60 and EVA 120 are applicable to vehicular services. Common models include speed at 3km/h.2. and background noise.
4. Such parameters include the penetration loss. Propagation-related gains or losses are constant. EVA30. ETU120. To obtain an objective value when comparing the link budget information of two equipment vendors. body loss. If required. 30km. EVA (Extended Vehicular Model A) and ETU3 (Extended Typical Urban Model at 3km/hr). and are related to the environment of radio wave transmission. 60km and 120km. EPA3 and ETU3 are applicable to fixed services or pedestrian speed services. different speed/condition can also be introduced and simulated according to specific needs. Items covered include multi-path conditions. feeder loss. ETU30. fading. Common channel models in LTE systems include EPA (Extended Pedestrian A).1 Channel Model
Channel models used for LTE are defined in 3GPP TS 36.101 where the test condition was specified.
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.2 Propagation Parameters
Propagation-related parameters have no relationship with technical systems or equipment vendors.

In an outdoor environment. Indicates a coefficient related to Effective height of Transmitter. Other parameters Indicates a coefficient related to the propagation distance and the effective height of the transmitter. The coverage radius of a base station is obtained based on the maximum propagation loss allowance in the link budget. Indicates a coefficient related to the receiver height. These two types of propagation models involve different factors.
45
.4. Indoor propagation model features low RF transmit power. except that the method for calculating the height of obstacles is different. such as buildings and trees. Indicate K1 and K2 in the none-line-of-sight condition. • 1-Deygout • This diffraction algorithm calculates the diffraction of a maximum of three obstacles. landforms and obstructions on the propagation path. Propagation in free space gives the lowest fade rate.2.
Method
K5 K6 Kclutter
This section describes the common propagation models in LTE planning. The fading of signals is larger than free space when radio waves propagate in open areas/suburban areas and fading rate is the largest in urban/dense urban areas. • 0-No Diffraction • Do not count the diffraction loss. • 2-Epstein-Peterson • This calculation method is the same as Deygout. Radio propagation models are classified into outdoor and indoor propagation models. Indicates a coefficient related to clutter loss.
K1-los K2-los K1-nlos K2-nlos K3 K4
Indicate K1 and K2 in the line-of-sight condition.3 Propagation Model
The radio propagation model plays a key role in the link budget. • 3-Deygout with correction • Correct the distance based on the Deygout calculation method. Signals fade at varying rates in different environments. Indicates a coefficient related to diffraction loss. the propagation models are generally based around modifying the following K factors. Although every planning tool will use slightly different method in their propagation calculation. • 4-Millington • This diffraction algorithm calculates the diffraction of only one obstacle. Method of calculating diffraction includes. must be considered. a short coverage distance and complicated environmental changes.

This function is related to the antenna height and working frequency of the terminal and the environment. The value of Cm depends on the terrain type.82 × lg(HBS) + (44. The unit is MHz. This model is applicable to the scenario when the antennas of the base station and terminal are mounted at considerable height and CLOS exists between the base station and the terminal. a(hss) indicates the terminal gain function. The unit is m. In this case. II. Free Space Model Free space indicates an ideal.9 × lg( f ) . The base station must be higher than the surrounding buildings.4 + 20log(d ) + 20log( f ) Where.3 + 33.13.6. The values of Cm in the standard Cost231-Hata are as follows: In large cities: Cm = 3 (as defined in Urban . The unit is m. d indicates the distance between the terminal and the base station.55 × lg(HBS)) × lg(d ) Where. Terminal antenna height: 1 meter to 10 meters Distance between the transmitter and receiver: 1 km to 20 km The Cost231-Hata model can be expressed by the following formula: Total = L . even. HSS indicates the height of the terminal antenna. or absorption occurs. and isotropic medium of space. Propagation losses are caused only by the energy spread of electromagnetic waves. refraction. The propagation losses in the free space model are as follows: PL = 32. the antennae of the base station and terminal can be mounted at any height. scattering. Satellite communication and microwave line-of-sight (LOS) communication are typical examples of free space propagation. Cost231-Hata Model Cost231-Hata model can be used in macro cells as the propagation model.a(Hss) + Cm L = 46. no reflection. If a clear line of sight (CLOS) exists between the transmit antenna and receive antenna. f indicates the carrier frequency. f indicates the working frequency of the system.I. then path loss complies with the free space model. d indicates the distance between the terminal and the base station. The application range is as follows: Frequency band: 1500 MHz to 2000 MHz Base station height: 30 meters to 200 meters. When electromagnetic waves are transmitted in this medium.9 . The unit is km. The preceding formula does not consider the impact of ground reflection. The unit is MHz. In certain conditions. The unit is km. and thus often underestimates propagation loss. HBS indicates the height of the base station antenna.large city in the related protocol)
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. LOS communication between the base station and the terminal is implemented.

In medium-sized cities: Cm = 0 (as defined in Urban – small city in the related protocol) In suburban areas: Cm = -2(log( f /28))2 .3 GHz and 2. a set of Cm has been created in the experienced model.5. K4 has to be a positive number Losses due to diffraction over an obstructed path(dB) Multiplying factor for log(d)log(HTxeff) Multiplying factor for HRxeff Mobile antenna height (m) Multiplying factor for f(clutter) Average of weighted losses due to clutter
The standard propagation model can be used for propagation model calibration through CW (Continuous Wave) test by using simulation tools. Standard Propagation Model (SPM) The standard propagation model is a model (deduced from the Hata formula) particularly suitable for predication in the 150MHz~3500MHz band over long distance (1Km<d<20Km) and is very adapted to GSM900/1800. III.6 GHz have exceeded the band range of the standard Cost 231-Hata model. 150 MHz to 2000 MHz.94 (As defined in Rural (quasi-open) – countryside where the terminal is unobstructed for 100 meters in the front in the related protocol) Since some of the working frequencies of the LTE networks are 2. diffraction mechanisms (calculated in several ways) and take into account clutter classes and effective antenna heights in order to calculate path loss.4dB (as defined in Urban – Suburban in the related protocol) In rural open areas: Cm = -4. the standard Cost231-Hata model must be corrected based on the CW test result.94 (As defined in Rural (open) – desert in the related protocol) In highways: Cm = -4. UMTS. it is based on the following formula: LSPM = K1 + K2 log (d )+ K3 log (H Txeff)+ K4 Diffractio nLoss + K5 log (d )log (H Txeff)+ K6 H Rxeff + K cluttrt f (clutter) Where: K1 K2 d K3 HTxeff K4 Diffraction loss K5 K6 HRxeff KClutter f(clutter) Constant offset (dB) Multiplying factor for log(d) Distance between the receiver and the transmitter (m) Multiplying factor for log(HTxeff) Effective height of the transmitter antenna(m) Multiplying factor for diffraction calculation. WiMAX and LTE technologies. The model may be used for any technology. in the actual LTE system design. CDMA2000.78 × (lg( f ))2 + 18.GENEX U-Net. According to the planning experience and actual CW test results in multiple scenarios.33 × lg( f ) -35. that is. Therefore.78 × (lg( f ))2 + 18.33 × lg( f ) -40. This model uses the terrain profile.
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.

is the most widely used radio frequency propagation model for predicting the behavior of cellular propagation in built up areas.
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. The expression of this model is as follows:
Where. ITU Indoor Model The IEEE documents provide a propagation loss model in the indoor base station environment. The original Okumura model for Urban Areas is a radio propagation model that was built using the data collected in the city of Tokyo. Frequency: 150 MHz to 1500 MHz Mobile Station Antenna Height: between 1 m and 10 m Base station Antenna Height: between 30 m and 200 m Link distance: between 1 km and 20 km. Japan. This model incorporates the graphical information from Okumura model and develops it further to realize the effects of diffraction. Okumura-Hata Model The Hata Model for Urban Areas. suburban and open areas. The model is ideal for using in cities with many urban structures but not many tall blocking structures.IV. Okumura model was originally built into three modes. This model is based on the Cost231 model. also known as the Okumura-Hata model for being a developed version of the Okumura Model. The traditional Okumura Hata model formula is shown below:
V. The model for urban areas was built first and used as the base for others The Okumura Hata model also has two more varieties for propagation in Suburban Areas and Open Areas. one for urban. reflection and scattering caused by city structures. The model served as a base for the Hata Model and the following assumptions apply to the use of Okumura Hata model.

In this case.
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.
The value of Lc is often 37 dB. offices) • Hollow pot tiles • Reinforced concrete • Thickness typ.3 GHz and 2.9
Caution: In an indoor cell. the value of n is 4.LFS Lc kwi n Lwi Lf b
indicates the propagation losses in free space. VI. the ray tracing method can be used to analyze wave propagation. obstructions in the propagation environment are often larger than the wavelength of the radio wave. Table 4-2 Weighted average for loss categories
Loss category Typical floor structures (i. indicates the constant loss. Such a right prism is identified by the top coordinate of the polygon at the bottom and height. the value can be changed to 3. windows) Internal walls • Concrete. The wavelength of the radio wave is several centimeters. according to the features and layout of the buildings on the 3D map. Therefore. indicates the number of penetrated floors. indicates the loss of neighboring floors. The basic idea of the ray tracing method is as follows: Determine the position of a transmission source. Ray Tracing Model The ray tracing model involves analyzing electric wave propagation by using the ray tracing method and obtaining the field strength of received signals through theoretical calculation. In normal indoor offices. indicates the loss brought by penetration through walls in i mode. Identify all the propagation routes from the transmission source to each receive point. geological information technologies allow you to identify each building in a city as a right prism in a high precision degree. For capacity calculations in moderately pessimistic environments.3
Lw1
3.e. brick • Minimum number of holes Description Factor (dB)
Lf
18. indicates the number of walls in type i penetration.6 GHz. Determine reflection and diffraction losses based on the Fresnel equation and the geometrical or uniform theory of diffraction. Some LTE network uses the higher part of the UHF band such as 2. indicates the experience parameter. In this case. that is.4
Lw2
6. In addition. < 30 cm Light internal walls • Plasterboard • Walls with large numbers of holes (e. the test point.g. often the antenna height of the base station or terminal is not specified and the deviation of shadow fading in log-normal distribution is often 12 dB.

For an indoor receiver to maintain normal communications. such as the antenna position. Due to the cost. height. the ray tracing model is used only in network planning in densely populated areas of large cities. and working frequency. In areas where no indoor distributed system is deployed. Table 4-3 Typical building penetration losses
Typical Penetration Loss (dB) Frequency (GHz) 1. building materials. penetration. diffraction. electromagnetic wave signals are obtained through diffraction and scattering. Table below lists the penetration losses associated with typical buildings. The prediction accuracy of the model is closely related to the precision of the digital maps and accuracy of site engineering parameters.the field strength of each route to each test point can be obtained. the signal must be sufficiently strong. Therefore. however. inverse radiation. The propagation modes of electromagnetic waves are as follows: direct radiation.
4. The ray tracing model is integrated in common commercial planning software. the indoor penetration loss is related to the incident angle. requires highly precise (at least to within 5 meters) digital maps that contain 3D building information. Perform the same point coherence stacking of field strengths of all routes to obtain the total received field strength of each test point. and down-tilt angle. Simulation software GENEX U-Net uses a 3D ray tracing model.2. The indoor receiver obtains radio signals in the following scenarios: • The indoor receiver obtains signals from an outdoor transmitter.6 Concrete Wall 15~30 Brick Wall 10 Wooden Floor 5 Thick Glass Wall 3~5 Thin Glass Wall 1~3 Lift Door 20-30
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.8~2. • The transmitter and receiver are located in a same building.4 Penetration Loss
Penetration loss indicates the fading of radio signals from an indoor terminal to a base station due to obstruction by a building. terrain. See Figure below
Figure 4-3 Indoor propagation scenario
The link budget is only concerned with the scenario in which an outdoor transmitter is used and the signals penetrate only one wall. This model. and scattering. direction angle.

In the link budget, penetration loss values depend on the coverage scenario. Therefore, coverage target areas are classified into densely populated urban areas, common urban areas, suburban areas, rural areas, and highways. Table below lists the area classification principles. Table 4-4 Principles for classifying coverage scenarios
Scenario Name Description In this scenario, buildings are densely distributed, and the average building height exceeds 30 m. In certain areas, buildings are distributed in order. The distance between buildings is narrow and is not fixed. The average distance between buildings is 10 m to 20 m. Most streets that are not main avenues are narrow. These areas are densely populated. In this scenario, the average building height is about 20 m. The average distance between buildings is similar to the average building height. Such areas contain a certain amount of open spaces and greenery. In this scenario, the average building height is about 10 m. Buildings are scattered and the average distance between buildings is 30 to 50 m. The streets are wide. Such areas may contain much greenery and many open spaces. In this scenario, buildings are scarce. The average building height is about 5 m. Such areas are likely to contain vast open spaces, fields, greenery, and roads.

Densely populated urban area

Common urban area

Suburban area

Rural area

The building penetration loss ranges from 5 dB to 40 dB. In link budget, if no actual test data in the target area is available, an assumed penetration loss value must be used. The final assumption is also highly dependent on local customer requirement. For example in sophisticated Asian Metropolis like Hong Kong, Singapore and Shanghai, the indoor coverage expectation will be very high, hence requiring a high penetration loss provisioning. On the other hand, in less developed market such as Africa and Latin America, customer expectation is lower so the penetration loss requirement can be reduced to reduce overall cost involved. During network planning, if no actual field testing data is available, refer to the penetration loss values listed in Table below. Table 4-5 Example of penetration loss
Scenario Densely populated urban area Common urban area Suburban area Rural area Penetration Loss 18 - 25 dB 15 - 18 dB 10 - 12 dB 6 - 8 dB

4.2.5 Body Loss
Body loss indicates the loss generated due to signal blocking and absorption when a terminal antenna is close to the body. This affects handsets in particular. Body loss depends on the position of the terminal. For fixed service, normally USB dongle is used. Terminals, such as indoor and outdoor CPEs, are often mounted on roofs, windows, or desks. An eNodeB antenna is mounted at a height of tens of meters, in which case body loss can be ignored as the body loss value is 0 dB. For mobile applications, especially PDA-based VoIP services, body loss must be considered and in this instance, the body loss is about 3 dB.
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4.2.6 Feeder Loss
Feeder loss indicates the signal loss caused by various devices that are located on the path of the antenna to the receiver. Any device using an external antenna for service provision at either the base station side or terminal side must consider feeder loss. If a USB dongle, an indoor CPE, or an outdoor CPE integrated with an antenna is used, feeder loss can be ignored at the terminal side, but not at the base station side. In the actual link budget, you must calculate feeder loss according to feeder type and length and connector type. Figure below shows the typical connections of the antenna feeder system in an indoor base station.

If a base station is mounted indoors, the link budget must include the losses of all devices from the RF port of the base station to the antenna interface, including the indoor jumper, connector, main transmission feeder, combiners, splitters and the outdoor jumper. If the RRU of a distributed base station is mounted on the tower top, you need to consider only the loss of the outdoor 1/2" jumper. In this case, the total cable loss can be greatly reduced to approximately 0.5dB.

4.2.7 Background Noise
The background noise of the LTE system is the same as that of other communication systems. The calculation formula is as follows: Nth = KTB. K indicates the Boltzmann constant. The value is as follows: 1.38 x 10 ^ (- 23)J/K. T indicates absolute temperature at a value of 290K. The result of KT is the density of the heat noise power spectrum and the value is -174dBm/Hz. B indicates channel bandwidth and in LTE, it can be 1.4MHz/3MHz/5 MHz/10 MHz/15 MHz/20 MHz

4.3 Equipment-Related Parameters
Equipment-related parameters include the base station, antenna, and terminal. The link budget parameters vary with the base stations, antennas, and terminals of different vendors. These parameters affect the link budget result. As a result, the downlink is unaffected in most scenarios.

4.3.1 Transmit Power
Transmit power includes that of the base station and terminal sides. The transmit power at the base station side affects the downlink budget. The transmit power at the terminal side affects the uplink budget. With the adoption of MIMO technology, two or more antennae are used at the same time at the base station for transmission. Therefore, the power combining gain must be considered. The formula for calculating the power combining gain is as follows: Power Combining Gain=10*Log(N) Where, N indicates the number of transmit channels of the base station. For example, when a base station contains two transmitters and two receivers, the power combining gain is 3 dB. Therefore, the transmit power in each sector (2T2R) is as follows: 46 dBm (40 Watt) in total for a 2x2 system with 20W from each transmit path
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G indicates antenna gain. The unit is dB. Two units are used to indicate antenna gain: dBi and dBd.
4. The antenna gain quantifies the degree to which an antenna transmits input power in concentration.4.
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.4 Antenna Gain
The antenna gain indicates the power density ratio of the signals generated from the same point by the actual antenna and ideal radiation unit when the input power is identical. The SINR used in the link budget is obtained from the system simulation result. NF is an important index used to measure the performance of a receiver. The NF of a common LTE terminal is generally 6 dB to 8 dB and the typical value used is 7 dB. In this formula. The dBi indicates the gain of the antenna compared with the isotropic radiator to all directions.
4.3. The demodulation threshold is related to the specific code modulation mode involved.3. In link budget tool. each of the subcarrier receiver sensitivity can be calculated by the following formula: Sensitivity = SINR + N floor + 10. reduce the lobe width of the radiation at the vertical plane and maintain the omni-directional radiation performance at the horizontal plane.3 Noise Figure
Noise figure is the ratio of the SINR at the input end to the SINR at the output end of the receiver. To increase the gain. Noise figure is highly dependent on both operating bandwidth and eNodeB type. A and B indicate the horizontal beamwidth and vertical beamwidth. the BLER chosen and whether other quality affecting features are implemented e. The value is -174 dBm/Hz.15. Figure below shows the relationship between dBi and dBd.2 Receiver Sensitivity
The receiver sensitivity indicates the minimum signal strength required to enable decoding by the eNodeB or UE receiver if there is no interference. and vertical beamwidth is as follows: G(dBi)=10*log[32000/(A*B)].
Figure 4-5 Relationship between dBi and dBd The relationship between antenna gain.g. MIMO and Coding repetition. horizontal beamwidth.log[15000] + NF SINR indicates the demodulation threshold of the receiver.3. Nfloor indicates the multiplication result of K and T and is the density of the thermal white noise power. The dBd indicates the gain of the antenna compared with the symmetric oscillator. The formula for the conversion between these two units is as follows: dBi = dBd + 2.

The figure below shows one example for Transmit Diversity system structure. the interference margin.3-1)
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. the LTE terminal market is dominated by USB dongle at this stage and CPE antenna gain values will be based on final product availability. MIMO gain is unique parameters of LTE technology.
4.4. especially in isolated towns. We recommend the 11-dBi omnidirectional antennas for coverage in rural areas.211 (fig 6. which helps increase coverage radius. CW0 and CW1 will be fed by 2 different payload streams.
4.4 LTE-Related Parameters
LTE-related parameters include MIMO gains. such as CDMA and UMTS. However. However. The 33° horizontal beamwidth antennas can be used for highway coverage. The 90° or 65° directional antennas can be used for base stations in suburban areas. the specified uplink/downlink rate at the coverage edge.1 MIMO Gains
MIMO configuration indicates that multiple antennas are used for signal transmission at the transmit end and signal reception at the receive end to improve the quality of service (QoS) for each subscriber. the MIMO technology can be classified into Single Input Multiple Output (SIMO) and Multiple Input Single Output (MISO) according to the number of antennas at the transmit and receive ends. gain similar to those currently available in 3G/WiMAX product is expected. The gain of such antennas can reach 21 dBi. The values of the interference margin and the fast fading margin in the LTE system differ from those in other systems. and the fast fading margin. The antenna gains of the terminals in the LTE system vary. since CPE antenna is external. For Spatial Multiplexing MIMO.
Figure 4-9 Transmit Diversity and Spatial Multiplexing MIMO TS36. For a traditional single-antenna system.We recommend the 65° dual-polarized 18-dBi directional antennas for the base stations that are distributed in densely populated urban areas and common urban areas. This results in a large difference in the coverage scopes of different terminals. the repeated coding gain.

That is. Power combining gain When multiple antennae (N) are used to transmit signals. a single data input stream is used to feed two separate antennae but it is equally possible to feed two different input data streams into this setup to provide higher data rate and it is the fundamental principle for Multiple Code Word (MCW) in LTE. the distance between antennae is often large. N transmit channels are available.4. space diversity gain. Spatial multiplexing gain The spatial multiplexing gain indicates the improvement of data throughput or transmission rate when the transmit power and bandwidth remain unchanged. In this case. That is. the total transmit power is equal to N times the transmit power from a single antenna signal transmission. 5. you can also increase the transmit power. 1. the higher the required edge rate. such as CDMA2000 EVDO. Multi-antenna technology can improve system capacity and coverage without largely increasing cost. 3. the receiving SINR can be improved. the signals in a single-antenna system suffer from deep fading. Array gain The array gain indicates an improvement in the average signal noise ratio (SINR) at the receive end when the total transmit power is the same. In a multi-antenna system. array gain. the smaller the cell coverage radius. 2. The spatial multiplexing gain is used to increase system capacity. however. Various multi-antenna systems can obtain the array gain. a power gain of 10log(N) dB can be obtained. Therefore. and implementation cost is complex and increased.
4. The array gain can be obtained through the coherent combining of various antenna signals. the interference signal is colored noise. This section describes the various gains brought by the MIMO. If a single antenna is used to transmit signals. This ensures that the signal fading of an antenna is independent. Interference reduction gain In mobile cellular communications system. You can obtain a spatial multiplexing gain by transmitting multiple parallel data streams over the same time-frequency resources. the requirements for the power amplifier are high. As a result. which is mainly used to increase the system capacity. the MIMO achieves a spatial multiplexing gain. 4.2 Cell Edge Rate
Similar to other wireless communications systems. This is because the multi-antenna technology gives the following gains: power combining gain. after the multi-antenna technology is used. You can combine the expected signals and suppress the interference signal through proper multiantenna spatial weight at the receiving end to improve the average SINR at the receiving end. In this case. However. the LTE features a rate layering feature. different from white noise. This is the basis of Interference Reduction Combining feature. inter-cell interference cannot be ignored due to the frequency sharing and multiplexing nature both within and between cells. In addition.In the example above. Space diversity gain Due to the fading nature of wireless channels. thus improving received signal quality. the SINR fluctuation of the received signals after combining stabilizes. The lower the
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. and interference reduction gain. WiMAX and HSPA.

and 64QAM are 2. As regulated by the protocols. In the link budget. More recent version are using per subcarrier as basis of receiver sensitivity and the conversion value is simply 10log10(12). 6 symbols equivalent (72 Res) will be the minimum overhead requirement per TTI. receive sensitivity of a base station is defined by the bandwidth of the RB which is 180 kHz. and 6 respectively. For example. and 2 streams for dual antenna port transmission mode 8 (port 7 and 8).Where. the larger the cell coverage radius. In previous version of link budget tools. In TDD system. 16QAM. Hence. Downlink ICIC also disabled). the settings of the uplink/downlink cell edge rates (in particular the uplink cell edge rate) will determine the final cell coverage radius. the lower the cell edge rate. For example. assuming there is no power control (i.required edge rate. the volume coding rate of QPSK1/2 is 1/2. Duration of each frame indicates the frame size. In case of BF. RB can be assigned down to a per TTI level (1 ms duration) Number of Different data stream transmitted is related to the number of data stream being simultaneously transmitted. Coding rate indicates the volume coding rate of the channel code. an understanding of edge coverage requirement is very critical from a network planning perspective. due to frequency sharing and time gap requirement for switching between uplink and downlink. downlink power control must be enabled also (which is executed at 20ms intervals based on UE BER reported value) and edge rate calculation will be more complex and
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. the modulation mode levels of QPSK. 4. If Downlink ICIC is enabled. Some of the factors that affect the edge rate in the LTE system are as follows: • Uplink/downlink TDD proportion • MIMO schemes chosen • eNodeB Power Amplifier power (affect downlink only) • Number of RB used at the sector edge • Modulation mode (1 of 29 coding methods) • Repeated coding times The formula for calculating the downlink cell edge rate is as follows: Cell edge rate_Phy = Number of Different data stream transmitted x Number of Resource Block assigned to user per frame x Number of available Traffic carrying Resource Element per Resource Block x Coding rate x Modulation model level / Duration of each frame . Number can be ranging from 1 (SFBC) to 2 (MCW 2x2). Number of available Traffic carrying Resource Element per Resource Block indicates the number of RE available for each resource block. This comes about due to the fixed power offered by UE (normally 23dBm) being spread evenly to the number of RBs involved in the modulation scheme assigned. the frame size in LTE networks is 10 ms. a maximum of 3 symbols (36 Res) can be consumed per frame (10ms) for control channel signaling purposes and there is at least 6 more extra RE can be used for Downlink Reference signaling per TTI (1ms). and the volume coding rate of 16QAM3/4 is 3/4. A minimum of 1 symbol (12 Res) will be required per RB for control signaling purposes. the value should be 1 for single antenna port transmission mode 7 (port 7 or 8). Modulation model level indicates the number of bits in the modulation mode. The smaller the number of resource blocks assigned. Number of Resource Block Assigned (a single RB is the basic resource assignment level) reflects the number of resource blocks used by user at the edge of the sector. In FDD system.e.

Nonetheless. Coordinated Multi-Point) are being proposed by the industry to reduce the level of interference over thermal increase which will further improves the capacity and throughput offered by LTE in the future. the orthogonal nature of LTE allows a smaller provisioning of cell breathing and interference margin when compared with WCDMA/HSUPA/ EVDO. In fact.4 Beam Forming
Currently. However. LTE uplink is orthogonal if it is within the same cell so there is no intra-cell interference. The interference margin in practice depends heavily on the planned capacity so there is a tradeoff between capacity and coverage just like other cellular technologies. FemtoCell.3 Interference Margin
Interference margin accounts for the increase in the terminal noise level caused by the interference from other users.4. It is mainly based on an adaptive beam patterns that acts to make the strongest point of main-lobe of the system output always be toward the direction of the expected UE and hence reducing the overall interference level for the whole cell. there is also a close correlation between actual traffic load and interference margin experienced by the network. due to the frequency division nature of LTE. the cell edge data rate requirement will still be the single most important factor in any cell planning activities.
4. The interference margin indicates the degradation of system receive performance caused by internal interference in the system due to system traffic.beyond the formula listed above.4.
Figure 4-10 Visualization of Beam Forming
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. we still need a margin for the other cell interference.g. Beam forming scheme is a signal processing technology that is used to direct radio transmission in a chosen angular direction. beam forming is only applicable for TDD version of LTE. Its algorithm is highly complex and utilizes channel state information to achieve array processing SINR gain.
4. Various techniques (e. The time synchronous version of LTE TDD on uplink and downlink also makes the implementation of beam forming more attractive than in LTE FDD. Relay. However.

or the “shadow fading margin”. To minimize the effect of shadow fading and ensure a certain edge coverage probability. certain allowances must be made. Figure below shows the relationship between the slow fading margin and cell edge probability.5.5 System Reliability
4.
4. Mode 7 (Rel 8) and Mode 8 (Rel 9). The main drawback here is there is also the requirement of either 4 (4x4) or 8 (8x2) transmit path from the eNodeB side which could make this more expensive to implement. Therefore. Fading caused by location (mainly from obstruction) far exceeds fading caused by time. Statistics repeatedly show that the median levels of received signals follow log-normal distribution with the time and location at a certain distance. this feature can significantly improve downlink system throughput and coverage performance and also provide good user experience by offering higher data rates. This is called the “slow fading margin”. There are two type of beam forming mode defined by 3GPP. the major concern for shadow fading is those caused by location changes. including: • Feedback from receiver • Estimation from reverse link assuming channel reciprocity (particularly true for TDD) As it is based on a multiple transmit configuration. and is thus called “slow fading”.Channel state information that is required includes: • Fast fading channel coefficient • Direction of arrival (DoA) of signal • CQI information Channel state information can be obtained by different way.1 Slow Fading Margin
Shadow fading indicates the fading brought by obstruction due to a building or a natural feature.
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. Shadow fading changes slowly. Mode 7 supports only single data flow so it can mainly improve coverage but Mode 8 can support multiplexing dual data stream as well which means it can improve both throughput and coverage.

such as rural areas and open areas. the standard deviation of slow fading is lower than that in suburban and urban areas. The formula for calculating the edge coverage probability is as follows: Edge coverage probability = 1 .Edge coverage probability) × Standard deviation of slow fading
The Q function is expressed as follows:
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. This spread of values approximate to the standard deviation of the signal strength at different test points from similar distances. Standard deviations requirement in Dense Urban area with highly integrated building layout and deeper indoor coverage requirement is even higher than typical urban environment.Figure 4-11 Impact of the slow fading margin on system reliability The difference found in the slow fading is reflected by the standard deviation of slow fading. In plain areas. The value ranges from 5 dB to 12 dB. The standard deviation of slow fading shows the distribution of the radio signal strength at different test points at similar distances from the transmitter. The standard deviation of slow fading varies with the geological form. Table below lists the typical standard deviations of slow fading in different geological locations.Q( Slow fading margin Standard deviation of slow fading )
The slow fading margin can be obtained through the following formula: Slow fading margin = Q-1(1 . Table 4-7 Typical example of standard deviations in slow fading
Scenario Densely populated urban area Common urban area Suburban area Rural area Standard Deviation of Slow Fading 10dB 8dB 6dB 6dB
The slow fading margin can be obtained based on the cell edge coverage probability and standard deviation of slow fading.

Use this probability to try the edge coverage probability PEdge for multiple times. Suppose that the area coverage probability of a cell is PCov. In fact. The figure below shows the point of divergence and the difference in path loss (dB) between the two assumptions vs distance (km)
Figure 4-12 Propagation Difference: Planar vs Spherical Earth Curvature Assumption
4. This is the distance where Planar Earth becomes spherical Earth distance from a radio propagation perspective.1 Features Overview
Below is a quick summary of specific features and their corresponding impact on the radio network link budget result if the features or functionalities are deployed
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.
4. b) The absence of soft handover gain between cells also means there will be NO macro diversity (soft handover) gain c) The slow rate of LTE power control (50Hz or 20ms) provides insignificant protection for fast fading condition. at higher latitude part of the Earth surface.5.6 Specific Factors in Link Budget Consideration
4. If the area coverage probability of the cell is PCov' = PCov’ the obtained edge coverage probability PEdge of the cell is the actual edge coverage probability of the cell.3 Absence of Fast Fading and Soft Handover Margin
It is also worth noting that in the system reliability part of LTE link budget consideration: a) Fast fading margin is absent in LTE as there is no WCDMA like fast power control gain.2 Effect of Earth Curvature
At larger propagation distances. the effect of earth curvature into radio propagation must also be considered. A 4/3 Earth radius multiplier is generally assumed for a distance larger than around 80km. it is not necessary to include a fast fading margin in the link budget. Hence.
4.The edge of coverage probability of a cell is based on area coverage probability.5.6. 80m high antenna will be required to ensure 40km coverage radius.

Once the pattern and power level is determined. At least 4 dB gain can be achieved through this data repetition. The application of this feature is ideal for lower data rate applications such as VoIP and Packet data services requiring slower rate. The code repetition rate will also be affected by the Redundancy Version chosen and it is currently based on Incremental Redundancy for LTE. TTI bundling will take precedent and the periodic reporting will be dropped accordingly.6.4. emulate the distortion occurring from the multi-path channels and. TTI bundling Gain is included as part of SINR in link budget estimation.2 TTI Bundling
By repeating the same uplink information.
4. This feature utilizes the spatial separation and characteristics of inter-cell interference to determine the power of the interfering UE which belongs to another cell.6. In situation where TTI bundling collides with periodic CQI/PMI/RI reports. lower SINR will be required by the receivers at the eNodeB. the victim cell can
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.3 Interference Rejection Combining
The concept of Interference Rejection Combining (IRC) is to regenerate the transmitted signal based on the estimated data from the previous receptions. finally subtract all regenerated interfering signals from the uplink received signals to obtain more reliable estimation of original users’ data.

the gain of IRC over MRC is not as significant. By outperforming Maximum Ratio Combining and MMSE receivers.
When Uplink IRC is used. Conversely. In comparison. IRC can provide more improvement than MRC especially when there are a reasonable number of receive antennae for IRC to execute the compensation. IRC is implemented in the baseband processing module (WBBP) of NodeB. simulation has shown a maximum SINR gain of 7dB can be achieved over traditional MMSE interference reduction method. IRC can increase the uplink users’ throughput significantly and hence improves the users’ experience. Therefore.then remove the interferer from the received signals. So in cases where there are only a small number of dominating interfering sources. It can reduce the interference impact of the neighboring users in the uplink. Maximum ratio combining (MRC) do not make use of the spatial characteristics of the interference when calculating antenna weighting.
Figure 4-13 MMSE and IRC SINR Requirement vs FER condition
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. IRC can enhance network coverage and provide better QoS for cell edge users. if there are a large number of equal power signals arriving at the receive antennae.

4 Reference Signal Power Boosting Gain
Power boosting in LTE is mainly perform on the Reference signal.6. as well as signaling channel. Radio planning engineers should pay particular attention to the following input parameters:
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. since the radio power is shared equally by all Resources element.7dB) or 4x (6dB) accordingly.
4. By increasing the number of Resources element being used as Reference Signal. the power allocation for each RE is fixed. However.6. 3x (4. Power Boosting value = 0 if there is no extra resources used.5 Remote Radio Unit and eNodeB Portfolio
We offer a comprehensive range of eNodeB and Remote Radio Unit Portfolio for various applications. the RS can be “boosted’ by 2x (3dB). Default Power boosting = 1 (2x) for network planning
Alternatively. Possible Radio configurations on offer range from 20W per carrier. Then the smallest radius is used as the final coverage radius based on the link balance principle. UL Traffic. reliability of information transmission can also be “boosted” not by radio transmission power but by adjusted to a lower modulation level (MCS adjustment).7 Summary of Variables inside Link Budget Tools
The link budget tool support the analysis for DL Traffic. depending on the actual length of the cable run from top of base station rack to the antenna location.
4. single transmit branch to two transmit at 40W each. The introduction of RRU allow the reduction of cable loss by up to 3dB for both uplink and downlink.4.

Please Note. 2600) Bandwidth: 1. 20M MIMO Scheme: Separately settable for Downlink (1x2.4M.25 at the Edge as UE power is shared across only 8 RBs for best Maximum path loss results against other MCS. 800. Typical value is either 43dBm (20W) or 46 dBm (40W). Below listed are some of the critical and “selectable” parameters from the Link Budget tool Duplex Mode: Option Frequency division duplex (FDD)/ Time division duplex (TDD). 10M. EVA. Cost231-Micro (Classic) and Cost231-Micro-Huawei. Cost231-Hata-Huawei. 2100. AWS. 1800. A is always refers to the transmit function of the device DL/UL Cell Edge Rate (kbps): Setting in accordance to the actual customer requirements DL/UL Edge MCS: Total of 29 Coding selection that can be chosen separately for DL and UL. 4x2 SFBC+FSTD) and Uplink (1x2. The Cost231-Hata model that is amended based on planning experience is generally used as the propagation model. We recommend UL MCS coding of QPSK 0. 3M. default is 2T2R) Design target area coverage probability.5dB for RRU) vs 3dB (standard cable length) or more (extended length) for RFU based configuration UE Transmit Power: Typical value is 23dBm +/. 1x4. referring to per TX path transmit power value. 15M. eNodeB cable loss: Value is dependent on cable configuration at customer site (0. In a AxB configuration. The minimum transmit power by this UE is -40dBm according to 3GPP TS 36. 1500. 5M. Further information can be seen in the following sections. Okumura Hata (Classic). High Speed Train (HST) Frequency (MHz): Frequency used in this system (700. However. please refer to detailed eNodeB configuration guide for final detail.2dB for a Class 3 unit. 1x8). UE Antenna Gain: Typical value is 0dB in the absence of any external antenna
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. TMA used: Yes/No TMA Gain: 12dB/24dB Morphology: Dense Urban/Urban/Suburban/Rural/Highway Channel Model: EPA. 2x2 SFBC. ETU. (Operator dependent ranging from 90 to 95%) The antenna in a base station is mounted at a height of 30 meters. 70% and 100% Propagation Model: Option include Cost231-Hata (Classic). 2300.101. The terminal antenna is mounted at 1. 850. Further information is available in the Propagation Model section below eNodeB Total Transmit Power: Customer configuration specific. 900. Okumura Hata-Huawei. 50%. As UL normally is the weakest link due to limited UE power. SPM.Type of MIMO multi-antenna technology used (At this stage. Common values are 30%. Actual UE power can be reduced by the modulation used. DL/UL Target Load: Target customer loading should be provided here separately for Downlink and Uplink so the desired interference margin can be incorporated into the link budget.5 meters high.

Link budget also assumes a uniform landform. the number of planned base stations will depend on the system simulation result. simple terrain. and even subscriber distribution. For a given coverage area. ideal site locations. and subscriber distribution. System simulation covers detailed landform distribution. the link budget result serves ONLY as the theoretical calculation result. The detailed coverage planning must be completed through system simulation. Hence. terrain type. actual site location. The calculated coverage radius is used for reference in simulated site distribution.
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.

The signals transmitted by one system are useless signals (that is. Spurious interference can reduce the signal noise ratio (SNR) of the interfered receiver. Spurious interference includes the out of band power leakage of the interference source.1. in saturation mode as the out of band suppression ratio of the receiver may
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. Spurious interference is generated by a transmitter and usually includes the thermal noise generated and amplified by the power amplifier (PA).
5.
Figure 5-1 Spurious interference Blocking Interference Receivers usually work in linear areas. it may also overdrive the receiver to work in non-linear state or even worse. Inter-modulation products can be generated during the multi-carrier operation and spurious signals can also be generated by frequency mixer. interference is one of the key elements that affect the network quality. amplified background noise. interference) to other systems. and transmit inter-modulation product.1 Basic Concepts
Spurious Interference Spurious interference refers to the additive interference generated by the interference source in the working frequency band of the interfered receiver.1 Overview
In mobile communication network. This section describes the basic concepts and the method to determine the influence of interference to sensitivity. When a strong interference enters a receiver. it becomes a common phenomenon that multiple mobile networks with different frequencies and modulation characteristics coexist in the same area. The interference to the LTE system is in multiple forms. With the development of mobile communication technologies.5 Interference and Guard Band Analysis
5.

together with the transmitted signal of the transmitter may also generate some inter-modulation products because of the non-linearity of the transmitter. This type of interference is called blocking interference. the inter-modulation product is generated because of the non-linearity of the metals. the inter-modulation product at the receiver is generated by the signals by the front end due to the non-linear circuit of the receiver. the interference signal may mix with the local oscillator signal and then generate the interference in the intermediate frequency (IF). In addition. When a strong signal is reflected back from the transmitting end of a transmitter back into the transmitter. blocking interference is generated by a strong interference signal out of the receive band that makes the receiver work in saturation state and then reduces the gains. multiple harmonic waves are generated on the received signal.
Figure 5-2 Blocking interference Inter-Modulation Interference When multiple strong signals with different frequencies enter a receiver at the same time. Generally. Unfortunately. When two strong interference signals are received at the same time. Blocking interference can reduce the receiver gains and increase the noise.be limited. When multiple signals with different frequencies transverse across conductors at the same time. this signal. the frequency of the inter-modulation product drops into the useful frequency band of the receiver and generates the inter-modulation interference. the frequency
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.
Figure 5-3 Inter-modulation interference Because of the non-linearity of the receiver and the limitation of out of band suppression.

If you want to eliminate the inter-modulation interference by installing a filter. ACLR was also formerly called Adjacent Channel Power Ratio and ACLR is specified in the 3GPP standard. ACS refers to the capability to receive the power of the local in band channel when the interference signal from the adjacent frequency exists. ACS is the ratio of the receive filter attenuation on the assigned channel frequency to the receive filter attenuation on the adjacent channel(s). ACLR is the dB value of C (total transmit power of the designated frequency point) subtracting D (total in-band leakage power of the adjacent channel). The adjacent channel may be used by the same system or a different system.
Figure 5-4 ACS
ACLR Adjacent Channel Leakage power Ratio (ACLR) is measure of transmitter performance and it is defined as the ratio of the transmitted power to the power measured after a receiver filter in the adjacent RF channel. it can be referred to as the ratio of the average power on the designated frequency point to the average power on the adjacent channel. you need to install a receive filter in the interfered system. ACLR represents the suppression capability of the transmit filter to the adjacent channel. Hence. As shown in the figure below.combination such as 2f1-f2 and 2f2-f1 of the two strong interference signals may drop into the band of the receiver and then generates interference. ACS Adjacent channel selectivity (ACS) is a protection index to determine the capability of a receive filter.
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. The bandwidth is determined based on the system in the adjacent channel. The capability to resist inter-modulation is a feature of the receiver. Alternatively. ACS is the ratio of the receive filter loss on the designated channel to the loss on the adjacent channel.

Figure 5-6 Near-far effect of the interference in the adjacent channel
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. The formula is as follows:
The interference in the adjacent channel affects both the system coverage and system capacity. When near-far effect exists. and may even cause the dead zone. interference from the adjacent channel greatly affects the system coverage. ACLR and ACS are usually considered together. therefore. resulting from both transmitter and receiver imperfections. The result of the consideration is Adjacent Channel Interference Ratio (ACIR) and ACIR is the ratio of the total power transmitted from a source (base station or UE) to the total interference power affecting a victim receiver.Figure 5-5 ACLR
ACIR It is difficult to separate ACLR and ACS because they coexist.

BW (channel bandwidth) and Guard Band. 1 dB decrease in the receiver sensitivity of the system is regarded as the threshold of interference. and the eNodeB receive noise figure is Nf (unit: dB).As shown in the preceding figure. the limiting design factor is the UE receiver. which implies that uplink ACIR ≈ ACLRUE. The reason is that ACSUE << ACLRBS. which will dominate the downlink interference. the interference power of system B to system A is even greater than the useful power of system A. the limiting design factor is the UE transmitter. which will dominate the uplink interference. In the uplink. OFFSET/BW/GB Figure below is the relationship of the Offset (frequency offset value).
Figure 5-7 Frequency offset relationship
5.2 Analysis of Background Noise
Assume that the eNodeB receiver’s IF bandwidth is Bw (unit: MHz). The reason is that ACLRUE << ACSBS. Thus. where. The noise level directly affects the eNodeB receive sensitivity. where the terminal cannot access the network. it is essentially the UE ACLR performance that is simulated.
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. In the downlink. A downlink simulation will thus essentially be a simulation of UE ACS performance. the eNodeB receive sensitivity decreases by 1 dB. (C/I) m is the minimum demodulation C/I. when the terminal in system A enters system B.1. The equivalent noise level of the eNodeB receiver is as follows: No = –174 + 10 log (Bw) + Nf (Unit: dBm) If the demodulation carrier-to-interference ratio C/I (unit: dB) of the eNodeB receive system for a particular modulation scheme (MCS). in an uplink simulation. In the system. which implies that downlink ACIR ≈ ACSUE. when the noise level rises by 1 dB. that is. the dead zone occurs. then the theoretical receive sensitivity of the eNodeB is as follows: So = No + (C/I) m. Therefore.

5 = 1.1
12 0. that is. The other values are calculated in the similar way: As shown in the preceding table. the interference level is also 1 w. when the original receive sensitivity of the system decreases by 0.04 0.37
10 0.5 w. handover.37 0. Table 5-1 Increase of background noise due to the presence of interference levels
Original system noise level / new interferer level (dB) Total noise level in system (compared with before) after new interferer is included (dB) Decrease of system receive sensitivity (dB)
20 0.04
16 0.97
3 1. When the interference level is equal to the original receive noise level of the system. the original receiver sensitivity of the system decreases by 1 dB. 0.
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. In actual component implementation level. The interference level is 0 dB lower than the original noise level of the system. call drop. after the system is interfered.5). WCDMA or WiMAX because it is the basic bandwidth that needs to be demodulated by each UE. the allowed interference level must be 10 dB lower than the original receive noise level of the system.76
0 3 3
In general.
5. 2. The total noise level of the system is 1 + 0. sensitivity is calculated on per subcarrier rather than the entire channel allocation as in GSM.97 0.5
6 0. the total noise level increase is as follows: 10 log (1.5 w. Therefore. In the broadband system.4
9 0. Assume that the original noise level of the system is 1 w: 1. When the original receive sensitivity of the system decreases by 0. The interference level is 3 dB lower than the original noise level of the system.4 0.5 times of the original noise level (1/103/10 = 0. that is.log(1+10^(△P/10)) △P = new interferer level compared to the original level in dB.1 0. the allowed interference level must be 16 dB lower than the original receive noise level of the system. that is. Therefore. the new total interference increase from original due to extra interferer can be represented by: 10. after the system is interfered.1 dB.76 dB.1. the interference level is 0. the influence of the interference to the system is that the interference adds to the original equivalent noise of the system and then raises the receive noise level of the system.5 w/1 w = 1. the total noise level increase is as follows: 10 log (2 w/1 w = 2) = 3 dB. Assume that the external receive intra-frequency spurious interference has the feature of the quasi-white noise.For LTE.3 Impact of Interference
Interference is one of the key elements that affect network quality.76 1. 3. the allowed interference level is generally 6 dB lower than the original receive noise coefficient of the system. The total noise level of the system is (1 + 1 = 2 w).5 0. receiver’s IF bandwidth and noise coefficient are affected by the specific circuits and can never reach the theoretical value or optimum value from a pure analog circuitry perspective.4 dB. Table 5-1 lists the receive background noise rise level due to the presence of the external interference at level specified. the receive sensitivity of the system decreases by 3 dB. Therefore. It deeply affects call quality.5) = 1.

14% 32.21% Decrease of Coverage Area 6% 12.91% 28.2.2 Interference Between TDD Systems
5.61% 48.21% 73.1 Interference between Different Carriers
Besides normal neighbor cell interference. which results in the decrease of coverage radius. Table 5-2 lists the relationship between the decrease of sensitivity and the decrease of coverage radius (calculated based on the classic propagation model Okumura-Hata. Table 5-2 Relationship between the decrease of sensitivity and the decrease of coverage
Decrease of Sensitivity (dB) 0.03% 48. The figure below provides a quick view of what will happen if there is asynchronous situation between different networks.
Figure 5-8 Interference due to Synchronization Misalignment
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.17%
5. How to reduce or eliminate interference is one of the key tasks in network planning and optimization.congestion.33% 17. The decrease of sensitivity is the most direct influence of interference. with the eNodeB antenna height of 30 m).33% 23.4 1 2 3 5 10 Decrease of Coverage Radius 3% 6. absence of synchronization is one of the main sources of interference between TDD based systems belonging to different carriers. network coverage and capacity. faulty transmitters and all the sideband interference scenarios listed in the previous section.37% 12.

2.4 km. Δf represents the 15 kHz or 7. By sampling the received signal at the optimum time. the delay in propagation can be resolved by using a smaller Cyclic Prefix of 6 (Extended CP) instead of 7 (Normal CP).
Figure 5-10 Normal vs Extended Cyclic Prefix
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. If this guard period is longer than the delay spread in the radio channel. Implementation of time synchronization equipment such as IEEE 1588v2 as discussed in Chapter three will help to resolve most of the asynchronous systems problem. In the downlink case. the inter-symbol interference can be completely eliminated if each OFDM symbol is cyclically extended into the guard period (by copying the end of the symbol to the start to create the cyclic prefix). The normal cyclic prefix of 144 x Ts protects against multi-path delay spread of up to 1.
5. difference in propagation delay will create time of arrival variation at the eNodeB and will result in intra-system interference as shown below
Figure 5-9 Interference due to Propagation Difference To resolve this problem in LTE TDD system.2 Interference within the Same Carrier
Even within the same network.5 kHz subcarrier spacing. The CP is a copy of the end of a symbol inserted at the beginning.5. a longer guard band period can be selected between DwPTS and UpPTS as discussed in Chapter 3. The longest cyclic prefix provides protection for delay spreads of up to 10 km.Scenarios (a) and (c) described above clearly indicate inter-carrier interference. Cyclic prefix lengths for the downlink and the uplink are shown in the figure below. For FDD system. the receiver can remove the time domain interference between adjacent symbols caused by multi-path delay spread in the radio channel.

Analysis of eNodeB->eNodeB Interference The eNodeB->eNodeB interference can cause serious performance deterioration when the isolation between systems is not good.3 Theoretical Analysis of Interference under Site Sharing
This section provides a simulation analysis of the system performance deterioration caused by the following four types of interference: eNodeB->UE. Filter. Analysis of UE->UE Interference When two systems are sharing the same site location. that is. When total ACIR of radio equipment (eNodeB. the most serious interference is the eNodeB>eNodeB interference. UE->eNodeB. and UE->UE when two systems share the eNodeBs. This section mainly describes the eNodeB->eNodeB interference and UE->UE interference. but only a small portion of the subscribers are affected and the influence is only temporary. the isolation between the UEs is in the worst scenario. Therefore. interference is always there. a 5 MHz guard band should ensure the network coverage and capacity losses are limited. eNodeB->eNodeB. when eNodeBs are co-located. it is assumed that the time percentage of the interference occurrence is 100%. both ACS and ACLR are required to be at least 33dB for a Class 3 and Class 4 mobile at +/. As ACIR increases. uplink coverage and capacity losses will occur.
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. In addition. most installations can meet the interference requirement under a 5MHz guard band setting. it is difficult to control the positions of the UEs through network planning. Combiners etc) is greater. When two UEs of two systems are very close to each other. if interference exists within the entire network.2. network coverage shrinkage and capacity reduction also decreases. From simulation result with no filtering. II. and UE->UE. Due to the “spill over” of transmitted signal into the receiving band. Assuming the situation that eNodeB of the interfering system is in transmitting state and the eNodeB of the interfered system is in receiving state. eNodeB>eNodeB. I.The interference scenarios can be classified into the following four types: eNodeB->UE. Hence. During simulation. As specified in 3GPP TS 36. as listed in Table 5-3 Please note the TDD system can be either WiMAX or LTE TDD Table 5-3 TDD/TDD interference classification
Interference Scenario (1) (2) (3) Interference Type eNodeB->UE eNodeB->eNodeB UE->UE UE->eNodeB Risk Normal Severe Severe Normal Victim Link DL UL DL UL
5. the network coverage reduction and capacity losses are limited. Based on our analysis. UE->eNodeB.101.5MHz from centre frequency. UE->UE interference comes about due to timing misalignment and one UE becomes the interfering system in transmitting state while another UE of the interfered system is in the receiving state. UE->UE interference does not seriously affect the network coverage and capacity. the downlink coverage and capacity losses occur as the interfered UE cannot perform in the best fashion. The network coverage and capacity losses caused by the other three types of interference are smaller than 2% even if the guard band is not provided.

From simulation result with no filtering.Table 5-4 Impact of UE->UE interference to the network coverage – Monte Carlo Spread
Downlink Coverage Probability Guard Band (MHz) 0 Frequency Band 2. as the eNodeBs’ separation and ACIR increase. the eNodeB->eNodeB interference can causes serious performance deterioration. Figure below shows the simulation result of coverage change due to distance variations between the interfering eNodeB and interfered eNodeB. the most serious interference is from eNodeB->eNodeB. However.2. UE->eNodeB.2%
Downlink Coverage Loss 0. This is especially the case when the eNodeBs are from different systems and operating under different bandwidth. the network coverage loss and capacity reduction gradually decrease. Hence.4%
5. Interference Simulation Analysis with Different ACIRs When the interfering eNodeB is close to the victim eNodeB. I.5 G No Interference from Other System 98. and UE->UE when two systems are not co-located.4 Theoretical Analysis of Interference: Non Colocated eNodeB
This section provides a simulation analysis of the system performance deterioration caused by the following four types of interference: eNodeB->UE. eNodeB->eNodeB. The network coverage and capacity losses caused by the other three types of interference are smaller than 2% even if the guard band is not provided.
Figure 5-11 Influence of distance vs coverage due to eNodeB->eNodeB interference
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. Assuming the offending eNodeB is in transmitting state and the victim eNodeB is in receiving state. our focus of analysis is the interference between eNodeBs. when the eNodeBs are not co-located. Coupling loss between the eNodeBs is calculated based on the free space propagation model by taking into consideration of eNodeB antenna gains caused by the direction angle and tilt. Both uplink coverage and capacity loss will occur.6% With Interference from Other System 98.

Figure 5-12 Guard Band definition between LTE and GSM
Figure 5-13 Co-Site GuardBand (MHz) between LTE Carrier of different Bandwidth &GSM
5. if FDD LTE is to co-exist with LTE TDD.5. With the introduction of SDR and SRAN product. the requirement of guard band for LTE has been further reduced in a co-located eNodeB. Moreover. a 5MHz guard band and separate antenna implementation is recommended. no guard band is required for co-location or non co-location if both systems are synchronized. if 2 LTE TDD systems that co-exist but not synchronized.
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.3 Guard Band Requirement: LTE-FDD vs GSM/UMTS
Configuration is simpler for FDD based systems because both LTE FDD and its neighboring technologies are based on frequency duplex and offer sufficient frequency separation between transmit and receive signals. However.4 GuardBand Requirement: LTE FDD vs LTE TDD
For two LTE TDD systems. a 5MHz guard band is still required regardless of whether they are co-located or not.

recovery of GSM spectrum is an essential step as most 1800MHz networks are still entrenched with GSM technologies. Current and the expected migration timeframe for different frequency band are shown below.5.2 GSM Spectrum Refarming
As shown in the figure above.5 Spectrum Refarming for LTE
5.5. An overview of capacity improvement and KPI achieved with one Operator is listed below. Tight Frequency Reuse (TFR) technology helps Operators refarm existing GSM spectrum for the deployment of LTE or UMTS networks. for Operators not in possession of new LTE spectrum.
Figure 5-14 Spectrum Refarming Expectation for LTE Deployment
5.5. As a result.
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. many networks are expected to perform some level of refarming so new LTE technologies can be deployed there. there is an aggressive drive from Operators in the 1800MHz community to implement LTE due to the relative abundance of spectrum in that band.1 Summary
Operators worldwide are looking forward to new LTE technologies deployment but not every one of them possess brand new spectrum required for LTE deployment. With this approach.

• Compact bandwidth need not to accord with standard bandwidth. Operators may opt to deploy LTE only in the core urban area but maintain their GSM system in the same spectrum at the fringe of the network.
5. radio engineer can introduce a buffer zone concept as shown below to the customer. Compact bandwidths for 5 MHz.5. • Compact bandwidth configuration helps operators make full use of anomalous frequency bands and reduce the waste of frequency fragment. Compact bandwidth produces higher throughput and better user experience. As a result. LTE may have to co-exist with other technologies (e. In order to ensure minimal interference is between the EUTRAN and GSM BTS (or Node B of UMTS). GSM) but at different locations.3 Introduction of Buffer Zone
Due to financial and/or traffic requirement.g. • Compact bandwidth is completely transparent to UE and has no impact to R8/R9 UE.Figure 5-15 Tight Frequency Reuse Results
LTE1800 eNodeB supports the compact bandwidths by strict filer and RB punching. 15 MHz and 20 MHz are supported.
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. 148Mbps downlink speed rate in trial test with 20MHz LTE bandwidth for LTE1800. 10 MHz.

6. there always needs to introduce new technologies. GSM900/1800 system has to use separate antenna to LTE 2.1 Overview
As mobile networks around the world evolve to offer more applications and services.
5.
5.6 Radio Access Technologies Co-location Strategies
5. traffic requirement. Different Frequency and Different RFU Co-location The different ports used for 2. In fact.6G and 900/1800 in the figures below also indicate the antennae are physically separable. based on the current antenna availability. interRAT as well as possible frequency planning arrangement but buffer zone concept will remain a feasible option for LTE and GSM co-existence. Co-location of multiple technologies can save both deployment and operation cost and with SingleRAN solution can definitely help to reduce footprint and TCO.6.6G.
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.Figure 5-16 Buffer Zone for LTE and GSM Co-existence Deployment
The final implementation will certainly be more complex due to coverage variations. This section plans to provide some high level recommendation for radio engineers on co-location strategies and configurations.2 GSM-LTE Co-Location Examples
Please note the following examples are just some of the possible frequencies combinations but the same concept can apply to other frequencies configurations I.

The following Configuration is not recommended due to the extra component requirement and addition insertion loss introduced.6G and GSM
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.
Figure 5-19 Co-Location Configuration Not Recommended for LTE 2.

g. Single RAN configuration)
Figure 5-20 Co-location Setup for LTE/GSM 1800MHz with RCU and without/with TMA
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.6G:
II. Same Frequency and Same RFU Co-Location The example below shows possible configuration of eNodeB when both GSM and LTE are operating at 1800MHz and the two technologies are sharing the same RF output (e.This antenna below for LTE2.

5m or vertical separation of 0.
OR
Figure 5-21 Antenna Physical Configuration Recommendation under LTE/GSM Co-location
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. a horizontal separation of 0. Physical Spacing Requirement Physical distance is the separation between the outer physical casing (not from the center of antenna) with both antennae being placed perfectly flat and parallel.6G with GSM900/DCS1800.2m between antennae can meet the isolation requirement for co-locating LTE at 2.This antenna below for LTE1800 and GSM1800 co-antenna solution:
III. Based on field measurement results.

In both examples. we recommend share feeder and two-port antenna.6.IV.5GHz) shown below are based on actual field measurement results and is in close (though not 100% similar) agreement with the theoretical data. The first example displayed the antenna separation required when the two technologies are sharing the same site so only antenna isolation separation is required. In general.four port antenna. • If different frequency and different RFU Co-Location.
WiMAX & LTE TDD Synchronization Scenario
Figure 5-22 Benefit of WiMAX and LTE TDD Synchronization
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. Different Frequency and Different RFU Co-location V.four port antenna. • If same frequency and different RFU Co-Location.3 LTE TDD and WiMAX Systems Co-Location
With the gradual migration of WiMAX network to LTE TDD worldwide. Two implementation examples (at 2.
5. it is also clear that a wider guard band between the 2 technologies will reduce the isolation requirement in antenna or site spacing. The 2nd example shows the isolation requirement when the 2 technologies are located at different sites and a physical distance separation is required. we recommend different feeder and co. we recommend different feeder and co. Antenna Feeder Solution Proposal • If same frequency and same RFU Co-Location. there will be medium term need for the colocation of the two technologies. it is recommended to synchronize both WiMAX and LTE TDD to remove the guard band requirement.

6 LTE Access Network Capacity Planning
6.1 Definition of Capacity
A commonly accepted definition of capacity is the one provided by Shannon which states that capacity is the maximum achievable set of rates in multiple access channels with an arbitrarily small probability of error. As “average” experienced quality we can mention the “average” delay of all transmitted packets or the “average” packet throughput. the sum of the transmitted data rates (downlink) or aggregated data rate is used. However. For instance.
The aim of LTE capacity dimensioning is to obtain the PS throughput supported in the network based on the bandwidth available and channel condition of each user. voice services have long been designed with a probability of error (non connection) ranging from 1% to 3% In the data centric world. with the increased availability of new services in wireless networks. As this metric represents a bound in performance. Since the required “average” experience varies across different services. user perceived quality or QoS is now also included in many capacity measures. the traffic mix chosen by the Operators will have a strong influence on the final maximum aggregate data rate that will be required and smart phone will further complicated the situation with their new user behavior pattern. the system capacity could be defined as the maximum aggregated data rate subject to the constraint that the average experienced quality of all flows in the system should be fulfilled according to a given target. in practice. A high level summary for capacity planning process and input requirement is listed in the diagram below:
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.

network planning engineers can determine which customer service level can be met. which has completely different behavior compared to feature phones. According to signaling statistics of operator S in Singapore.Figure 6-1 Overview of EUTRAN Capacity Planning Process
Examples of “Scenario Parameters” and “Equipment Parameters” are listed below. and the service heartbeat mechanism periodically communicates with the application server. They frequently changes state between "idle" and "connected". its fast dormancy feature forces the terminal to switch to an "idle" state every six to eight seconds in order to save battery power. Nevertheless. one smart phone creates 14 times the signaling load of a feature phone.
Figure 6-2 Examples of Parameters Related to Capacity Planning
Most of these parameters are similar to those used for 2G/3G network dimensioning and by carefully considering the contribution of all these parameters. is going to add a new level of challenges to planning engineers. the increasing popular level of applications like twitter will hasten the evolution of customer behavior and
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. In addition. the arrival of smart phone.

with Guaranteed Bit rate vs with Non Guaranteed Bit rate. RT (Real Time) services are characterized by the short time response between the communicating parts and they generally required an acceptable GBR. how customer chooses the proportion and combination of these different services will be translated into bits per second requirement for the customer network. The table below shows the relative priority. Although the dynamic nature of E-UTRAN capacity limiting factors listed below will affect the final user throughput and capacity. On the other hand. information loss is not tolerable.e. it is essential that the network is dimensioned properly in the design stage to reduce the impact of services offer booking and short term surges in services due to unexpected events. there are two main classes of service type.. However.2 3GPP Services Classification
Being a data centric technology. NRT (Non-Real Time) services do not have tight requirements concerning packet delay although high packet delays are unacceptable.3 EUTRAN Capacity Limiting Factors
In general. Therefore. As an example of this kind of service we can mention Voice over IP (VoIP). NRT normally is Non-GBR services. Hence. i. Web browsing is an example of an NRT service.
6.traffic model in the next few years. In general. Average subscriber usage at busy hour has rapidly increased from the low 10kbps (since R99/1xRTT) to be in the mid to high 30kbps right now. the following are the major factors that will contribute towards the limitation of EUTRAN capacities:
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. applications of this type must have error-correction or recovery mechanisms.
6. LTE has well defined classifications for Quality of Service. expected error rate and delay for each QoS class. These services have strict requirements regarding packet delay and jitter. when transmitting NRT services the major constraint is the information integrity.
Figure 6-3 3GPP Service Level Requirement Definition
From a EUTRAN design perspective.

there is a strong relationship also between the number of users and overall cell capacity.3. coverage is always a leading indicator of the likelihood of getting good service level. the per user throughput will decrease as the number of users in the cell increases due to resources sharing On the other hand.
6. Germany white spot wireless DSL project)
6.6GHz is more likely to be used and is best suited for urban environment which also demand higher capacity within a smaller area.2 RF coverage .when it comes to capacity planning. Besides external interference.3 Impact of Interference on Capacity
Interference is always a main contributor to capacity degradation in 1G to 3G cellular network and LTE is no difference. The figure below gives a high level view of the likely difference in coverage strength offered by the different major frequency band currently chosen for LTE deployment. 2. Although intercell interference will not be reflected by RSRP level.RSRP
As in any other cellular technologies. field trial results confirmed the overall cell downlink throughput continues to degrade as the
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. either in the form of throughput or call quality and LTE is no difference in this regard.3. 800MHz is more likely to be used for rural applications due to the more extended coverage (e. it is still a strong indicator of throughput level as long as the initial radio network was designed properly. On the other hand. The frequency propagation and penetration characteristics will determine the number of sites that need to be built in order to cover the designated area chosen by the Operator.g. Reference Signal received power is a common measurement that can provide the coverage quality level.
Coverage Gain with Low Frequency
Figure 6-5 Difference in Propagation Loss due to Frequency Band
With its shorter coverage range. Field trial results confirmed that although overall cell uplink throughput is stable. This in turn will decide the final capacity that can be offer for commercial services.

number of users increase.
6. Please refer to the specific product dimensioning guide for detail. Examples of such limit include maximum throughput. However. the availability of UE power will also determine the uplink coverage and throughput a user can achieved.
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. the capacity of the S1 and X2 links will play a critical role to the overall throughput and capacity available to final users. Downlink ICIC or efficient power control) as the most important factor in cell capacity protection.2dB)
6.
6. EUTRAN planning engineers must also be aware of the limit due to hardware specific capacity. Most users are expected to be using Class 3 mobile (23dBm +/. Detailed dimensioning procedures and their impact will be discussed in the section 6. The likelihood of cell edge users overcoming neighbor cells interference will also be highly dependent on the radio transmitter power installed and available at the cell site.3.9 Application of Special Antenna Technologies (MIMO/BF/V MIMO)
As already discussed in Chapter 4.7 Base Band Channel Card Processing Capacity
Similar to other technologies.8 S1/X2 Capacity
As the pipeline connecting eNodeBs to the packet network.3. The impact is especially obvious for users at the cell edge as the eNodeB is most likely need to change the coding allocating due to the radio power and quality received by the cell edge user.3. Trial data below confirm the need of high SINR in order to achieve a high throughput in the downlink level and adaptive modulation technology is perfect to meet such requirement.7. This clearly identifies interference control (either through cell coverage control.
6.5 to section 6.3. Although product offers superior capacity. the most commonly used power in LTE eNodeB is 20W and 40W at this moment. At the same time.
6. the final values may vary between different eRan releases due to continuous improvement. Conversely.
6. the per user throughput also decrease as the number of users in the cell increases due to resources sharing. MIMO and Beam Forming are critical features in determining the actual link budget required for the Operator’s network.6 Spectrum Bandwidth Availability
Operators will need to determine how much spectrum bandwidth is available for the deployment of LTE services and there is a direct correlation between available spectrum and the cell capacity for both Uplink and downlink. As discussed in Chapter 4.5 Radio (Transmitter) Power Availability
The selection of radio power will have a significant impact on both the coverage and capacity of an LTE cell.3.3.4 Signal Interference Noise Ratio and Adaptive Coding
These two factors are extremely correlated and are both critical factors influencing the overall capacity of the cell and the network. maximum number of active users and CPU loading. these two features are also critical features from a capacity perspective as they can also improve the efficiency of frequency reuse and reduce the intra-frequency interference within the same cell as well as neighbor cells.

Figure 6-6 Graphical View of 2x2 MIMO in Operation

In addition, We offer a separate antenna related technology in uplink, which is focusing on capacity improvement. This feature is called Uplink Virtual MIMO and it achieves uplink throughput by allocating same RB for different uplink users. Uplink Virtual MIMO can increase overall uplink spectral efficiency and hence increasing the overall uplink throughput. It is similar to a feature called CSM for WiMAX. The network will carefully select two users with the following characteristics: • Highly uncorrelated in the Uplink • Offer the best capacity improvement to the cell after combining • Highest Max PFair output when the 2 users are combined together These selection criteria will allow users with the most uplink data need and most uncorrelated to be chosen first. Since those two users are highly uncorrelated, they can be easily removed from each other’s overall signal.

Figure 6-7 Graphical view of Uplink Virtual MIMO

6.3.10 Scheduling Mode
Scheduler is one of the key RRM algorithms designed to maximize the radio resource usage and capacity availability while meeting the QoS (Quality of Service) requirements of different applications and users in both uplink and downlink. Because different operators may have different traffic mixes and strategies of utilizing their resources, the scheduler is flexible and configurable in order to meet various goals. The design goals of the scheduler include maximization and/or guarantee of the following: 1) Cell throughput 2) Cell edge user throughput 3) VoIP capacity 4) QoS satisfaction rate for various services. Scheduling algorithm enables the system to decide the resource allocation for each UE during each TTI. Scheduler
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6.3.11 Actual Cell Site Placement in Relation to Traffic
Similar to other cellular technologies, coverage provided by Macro vs Hotspot (micro/pico) cells and their vicinity to main user groups will have a significant impact on the final offered capacity. For example, limiting spectator traffic to a dedicated stadium only cell means most of its eNodeB power will be available to provide a better service rate instead of spending most of the energy travelling through air from external macro cell. The actual capacity degradation due to the amount of users and their distance from cell antenna is highly variable and will also depend on the actual traffic distribution at the time. A general rule is the further the users are from the cell antennae, the lesser the amount of capacity a cell can offer. Capacity will be degraded even more if more users are to be located towards the edge of cell coverage and it is possible to have a capacity degradation of up to 25% in some situation.

6.3.12 UE Capability
It is important to remember that the composition and penetration of various UE types will also have an impact on the final achievable cell throughput level. A high concentration of relatively low end UEs will result in low resources utilization efficiency, thereby bringing down the overall cell throughput. This will certainly be depending on when the network is launched, pricing model of Operators as well as UE vendors as well as the form factors of UE offered at the time. The figure below summarizes the capability of UEs by their category. E.g. only Cat-5 UE can support 64QAM on uplink initially and will affect user uplink throughput.

6.3.13 User Traffic Mix and Call Modelling
As listed in previous section, LTE has 10 Quality of Service Classifications. The more freedom eNodeB has in user throughput allocation (represented by Best Effort only users), the more likely the cell will have a higher aggregate throughput as the scheduler can adjust the resources allocation more appropriately based on radio condition. On the other hand, the more Guarantee Bit Rate users are present in the cell, the more likely the cell will have a reduction in its average aggregate throughput.

6.3.14 Time Slot Allocation for Uplink and Downlink – TDD specific
The time division nature of LTE TDD will also require radio engineers to consider how time slots are shared between uplink and downlink based on both customer input as well as commercial users usage pattern between uplink and downlink in that country. This will have a direct impact on the EUTRAN capacity. There are 7 time sharing configuration between Uplink and Downlink in LTE TDD as defined by 3GPP. They are shown in the figure below and in summary, they are (DL : UL) - 1:3 or 2:2 or 3:1 or 2:1 or 7:2 or 8:1 or 3:5

Figure 6-9 Uplink-Downlink Time Sharing Configuration Schemes

Besides time sharing configuration, there is also a need to define how uplink and downlink pilots are configured based on the Guard band requirement. The guard band duration is also a direct result of propagation delay requirement due to the designated cell coverage radius. Inadequate guard band provisioning will result in direct interference between users within the same cell due to difference in signal delay arrival. 3GPP has defined 9 different guard period configuration schemes for Operator to choose. They are listed in the figure below.

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3. due to large cell radius coverage).g.4 S1 Bandwidth Dimensioning Procedure
The figure below denotes the location of the X2 and S1 link with respect to the other network components within the LTE network
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.Figure 6-10 Uplink-Downlink Pilot Time Slot and Guard band Configuration Schemes
6.15 Cyclical Prefix Allocation
In order to accommodate extended propagation delay (e.
6. This will result in the reduction of OFDM symbols that can be carried per time slot and therefore reducing the overall sector capacity. a lower order cyclic prefix value of 6 can be used instead of the common value of 7.

Figure 6-12 S1 Interface Composition
6. Main X2 dimensioning factors that need to be considered (in eRan2. However in realistic network implementation. and the user plane.0 and 2. where GPRS tunneling protocol for user plane (GTPU) is adopted as the tunneling method.Figure 6-11 E-UTRAN Network View
In general. the control plane.5 X2 Bandwidth Dimensioning Procedure
X2 is the interface between eNodeBs and the bandwidth requirement is very complex. it is most likely that there will not be any direct connection between eNodeBs. the traffic on S1 interface is divided into two different plane. Instead. the X2 data will be combined with the S1 data and transport back to aggregators residing in the switching centre before being rerouted to their target eNodeB.1) include: • The frequency of handover between eNodeBs • The duration time of handover • The overlapping nature between eNodeBs • Hysteresis setting at cell level
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. which uses SCTP (Stream Control Transmission Protocol) developed by IETF for the purpose of transporting various signaling protocols over IP network.

Hence.
6. excessive delay in S1 or X2 routing will definitely affect the service quality and user performance of higher layer applications. meaning data users at the edge of network are likely to be “offloaded” to UMTS/GSM network • UE redirection from existing UMTS/GSM network back to LTE is unlikely to be available for most customer network upon initial launch due to new software requirement in UMTS/GSM network. the throughput of X2 is estimated to be 3% of the throughput on S1 in order to simplify the dimensioning process. • LTE networks are unlikely to have contiguous coverage throughout the entire customer network especially outside certain urban area in most cases. routing delay may be inherent in Operator’s non cellular core data network and this will create impact on throughput although it is not as severe as in infinite HAQR. • SRVCC (Single Radio Voice Call Continuity) will come into service once IMS becomes a standard component in Operators’ network • On the other hand. once VoLTE becomes widely available. the amount of LTE traffic should be reduced as VoLTE terminal is unlikely to be commercially available till late 2011.• Average service rate and packet size per handover • Signaling overhead in control plane of X2 interface The throughput on X2 is negligible compared to that on S1. Even in normal networks.7 Inter Radio Access Technology Handover Considerations
The offloading and handover impact due to Inter-RAT must also be considered as part of the overall network capacity planning process.
6.
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. the traffic level in LTE will also increase significantly but likely to be in a gradual fashion. Similar to the S1 control plane throughput calculation. Resolution of such problem is beyond the responsibility of access engineers.6 Impact of Latency of X2 on Cell Throughput
If infinite HARQ process is allowed (as a theoretical study). Various reasons to support this idea and they are: • IMS are most likely to be absent in many early LTE network so CSFB are likely to be required to carry voice traffic.

The final delay period could also depend on individual UE manufacturer’s rescanning algorithm. Different Inter-RAT handover algorithms are listed below:
Figure 6-13 Different PLMN Idle Handover
Figure 6-14 Different PLMN Dedicated Mode Handover
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. this rescanning could be hindered by any active connections to UMTS/GSM during this period.• Although LTE capable terminal is required to rescan for LTE network after 6 minutes.

Create a simulation project. Set the User Equipment. User Profile setting. Set the Transmitter global parameter. Import maps—set the coordinate system. For existing sites. Mandatory. default parameters are automatically set but need adjustment. Mandatory. Service setting. 8. Set network parameters. Set the Feeder Equipment. 12. Mandatory. directly copy and paste the site parameters. It is not aimed at replacing the U-Net user manual but is intended to give an overview of U-Net operation.
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.7 U-Net Simulation and Operation
7. 9. Mandatory. Mandatory. Optional. Set the parameter of the traffic model.2 Simulation Process
Below is a quick summary of the most of steps that need to be taken in a simulation process
Simulation Process 1. Set the Predictions global parameter. Mandatory.
7. 7. Optional. select one from two. Set prediction parameters. Import site parameters. Set the parameters of the eNodeB equipment. The antenna of the eNodeB is mandatory and that of the terminal is optional. Mandatory. select one from two. Set the Clutter Classes parameter (standard square deviation of shadow fading). Set the parameters of propagation models (including the propagation models for different geographic types). Mandatory. 10. 6. Mandatory. 3. 13. Mandatory. Set the Frequency Band. This chapter includes ten sections to give an overview of what U-Net V3R6 can offer from a LTE FDD radio planning perspective as of end of 2010. Environment setting. 2. Mandatory. Mandatory. Set the eNodeB Equipment.1 Introduction
This chapter describes the basic information of the U-Net in terms of use method. meanings of common parameters. Terminal setting. Planning information for LTE TDD is not yet available and will be added later on once the planning tool is approved by the responsible RNP experts. and relations between parameters in software. Monte Carlo simulation setting. Import the antennae of the eNodeB and terminal. Monte Carlo simulation setting. 5. 11. Optional. 4. Set the Transmitter table. For new sites.

7.3 Creating Project
1. Run the U-Net. 2. Click on the toolbar or choose File>New. The Project Templates dialog box is displayed.

3. Select LTE and then click OK. The LTE U-Net project is created. 4. Click on the toolbar or choose File>Save. The Save As dialog box is displayed.

5. Select the storage directory and name of the project from the Save Project File dialog box and save the file, as shown below.

7.4 Geographical Information
7.4.1 Quick Import Function
User can make use of the Quick import function of U-Net under Maps by Right mouse click on Map

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Maps related information can then be imported individually via highlighting each of the following

Model. Indicates the height that above the DTM map if the DTM map is imported. The indoor loss is used when buildings exist.5 Equipment Parameter
7. The standard deviation is used to calculate prediction items. Functional when the SPM model is used and not functional when the Cost-Hata model is used.5.5. The value is consistent with that of the Estimation tool. the standard deviation of Model is used. Statistics that indicates height of the clutter above the ground.Parameter Code Name Indicates the code of the clutter class. transmitter and UE in the U-Net. The figure below gives a high level view of the relationships between various parameters in U-Net
7. C/ I standard deviation Penetration Loss
7. If it is not C/I prediction. If the indoor coverage is considered when estimating. The standard deviation is used to calculate the shadow fading margin. indoor penetration loss should be considered. with a common value of 8-20 dB.
Description
Height
Indicates the average height of the clutter. Indicates the indoor loss of each clutter class.1 Overview
This chapter describes the setting and related properties of equipment like the eNodeB.2 Network Settings
I. Unit: dB. Unit: m. Value range: 4-10 dB. Setting Frequencies Path: [Explorer / Transceiver / Frequency Band]
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. Indicates the clutter class.

The channels between the first channel and last channel that cannot be used. number normally starting from 0 (or any positive number). Channel bandwidth. The last channel that can be used. Indicates the start frequency in the time division duplex (TDD) mode and the downlink start frequency in the frequency division duplex (FDD) mode. Indicates the start frequency. The first channel that can be used.Field Name Channel Width (MHz) Start channel Last channel Excluded channels Frequency (DL) (MHz) Frequency (UL) (MHz)
Description Indicates the frequencies and has no impact on the calculation. Indicates the FDD uplink start frequency.
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. Indicates the bandwidth of each sector. Related to the frequency width and channel bandwidth.

users can also view the MCS value format used in U-Net.
By clicking Cell reception equipment or Default UE reception equipment and then followed by clicking on MCS threshold. Make sure all fields are displayed as well.Users can then match the required MCS table accordingly to Uplink and Downlink table defined above through the selection tab shown below. Setting MIMO Configuration Path: [Explorer / Data / Transmitters] Set the number of Tx/Rx antennae per eNodeB transceiver here.
Path: [Explorer / Data / Traffic Parameters/Services/LTE/MIMO] Also set the number of Tx/Rx antennae per transceiver here for different services type
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. V.

Indicates the number of Tx antenna.
Description
Indicates whether space division multiplexing is supported.Field Name Tx_Antennas Rx_Antennas SM_Supported SM_Gain (dB) Indicates the name of MIMO. Under U-NetV3R6 only downlink spatial multiplexing is enabled.
All MIMO parameters must be set correctly in order to allow simulation to be performed correctly especially for MCS function. Indicates the number of Rx antenna. This will allow simulation to switch between SFBC and MCW where appropriate.
Path: [Explorer / Data / Traffic Parameters/Terminals/LTE/MIMO] Set the number of Tx/Rx antennae per transceiver here for different terminal type
Then enable Space Multiplexing by checking the box under LTE Terminal folder.
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. Indicates SM gain.

The results should appear as below after importing file with correct format.
Similarly.
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. Cell and Transceiver tables can be imported in similar fashion.

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. Examples are shown in the diagram below and detail information on these models can be found in Chapter 4.5 Viewing “Hidden” Parameters
Many parameters are not shown in the default U-Net display.5. They can be recalled using the following steps:
By checking the corresponding box.6 Propagation Model Selection
U-Net has already built in a number of propagation models so users can just select them without any extra adjustment.7.5. the actual label will appear in an excel like table after the selection has taken place. Extra fields can also be added according to the user’s requirement
7.

diffraction method as well as effective height definition.User adjusted propagation model can also be created by modifying the individual K parameters.
Drive test/CW data can be imported and then used for calibration which is performed in the following steps
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.

After choosing/creating an appropriate model for network design. this model can be assigned to each cell in the network accordingly within the Cell table Path: [Explorer / Network/ Transmitters / Cell /]
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.

Upon completion make sure the right selection is chosen under LTECell/Propagation Model

This will allow each clutter type to be assigned to an appropriate morphology type (Dense Urban/Urban/Suburban/ Rural) and saving the time needed for radio planner to assign different model for different cell.

7.5.8 Impact of Parameter Setting on Prediction and Simulation
The table below summarizes the impact on prediction and simulation results by each of the critical parameters listed for U-Net V3R6 GA version (V300R006SCP300)
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7.6 Engineering Parameter
7.6.1 Power Setting
There are 4 main power related parameters that need to be adjusted and they are under Path: [Explorer / Network/ Transceiver / Cell /]

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I. Max Power The maximum power from the eNodeB by summing all the transmit paths. If eNodeB is a 2x20W configuration, the Max power is 46dBm. An eNodeB of 2x40W will be 49dBm II. RS Power This is the power allocated to the Reference signal and will be dependent on the bandwidth as well as the number of RE (15kHz) channel allocation. For example, if there is 2x20W at a 20MHz spectrum while Power Boosting (PB) = 1, then the RS power RSRE Power = 43dBm (20w) – Log10 1200 (100 RB) + 3 (PB = 1) = 15.2dBm Since different RE will be used for RS at different antennae, U-Net is avoiding any uncertainty in UE RSRP measurement methods by providing only a single path RS power. It is likely the actual RSRP measured in the field be higher due to the implementation of downlink MIMO. III. PB Power Boosting with a range of [0, 1, 2, 3], this value is defaulted to be 1 and represent the number of extra RE used for the addition of Reference signal transmission.

IV. Other Channel to RS Power value of other channels such as PCFICH, PHICH, PDCCH, PBCH, SCH can all be offset against the Reference signal power.
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Radio planner can then choose to “commit” the resulting values or not as the Actual Load and Actual IoT. a value of 1 (100%) is given II. Actual IoT (UL) Increase in uplink interference level used in Prediction. Neighbor load Impact estimation due to interference from Neighbor cell can be set under Properties function of a particular
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. IV. Typical value is 2-4dB which corresponds to the uplink interference margin in link budget.7. Target Load (UL/DL) The number of RB allowed to be used for Simulation of traffic in cell (out of all available RB). Normally. a value of 1 (100%) is given. U-Net will gather Target load (UL/DL) and Target IoT (UL) from the configuration information.2 Load Setting
System loading will have a determining factor on throughput in an LTE network. Target IoT (UL) Increase in uplink interference level created by Simulation traffic. Normally. Typical value is 2-4dB which corresponds to the uplink interference margin in link budget.
During Simulation.
V.
III. Path: [Explorer / Network/ Transceiver / Cell /]
I.6. U-Net allows user to simulate the network with loading in both forward and reverse directions. Actual Load (UL/DL) The number of RB allowed to be used for Prediction of traffic in cell (out of all available RB).

Normally.3 Frequency Planning
Path: [Explorer / Operation/ LTE Frequency Planning /] Activate the frequency planning function through the following Tab
The available Polygon or traffic area will appear for selection
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.6. Neighbor load value will be of 50 – 75%.
7. If Neighbor load is not selected.Prediction. Path: [Explorer / Operation/ Prediction]. “Actual Load” value of the neighboring sector will be chosen by U-Net in neighbor load calculation.

ensure the band and channel index shown below are selected
I. user can select N Channel index (N = 3 under 1x3) and frequency planning function will allocate different Channel to different cell. With multiple frequency reuse (U-Net only support 1x3 currently).
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. all cells will be labeled as using Channel 0 only. Channel Index Path: [Explorer / Network/ Transceiver / Cell /Normal Parameter] Value of Channel Index will determine the frequency reuse pattern.Before running the allocation. Under Single frequency reuse (1x1).

then select the Channel index that can be used for frequency planning before “running” the allocation. Edge Frequency Style The style corresponds to the frequency pattern chosen and only applicable to (1x1). the frequencies will be allocated according to the table below.
III. An example output is shown based on 1x3 selection where Channel 0 -2 are chosen. Basically.
II.In U-Net.
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. Upon completion. it shows which 1/3 part of the frequency has been chosen by Automatic frequency plan for the downlink and uplink of a particular sector. ICIC Switch Path: [Explorer / Network/ Transceiver / Cell /Advanced Parameter] ICIC function for Uplink and Downlink can be enabled separately for simulation. A graphically representation of style for downlink is shown below. the first step is to select the frequency Reuse pattern.

7.5 Antenna Property
Path: [Explorer / Data / Antenna]
Most common antennae categories are already included as part of U-Net standard tools without any need of new input. 30) exceed the max schedule users (e. Max Schedule User Controls how many users can be scheduled within a single TTI (1ms) for uplink and downlink separately.g.
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.6.g. 10). Default value is 10. However. U-Net scheduler can simulation multiple TTI condition if the number of data transferring users (e. user may also need to configure special antennae due to customer’s requirement by incorporating data into the 4 tables under Antenna – New option.III.

This parameter is not used in calculation. all these values are for labeling purposes only and don’t affect prediction results
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. (dB)
Other Properties The U-Net defines three parameters for antenna data: Beamwidth.
Att. Unit: dB. However. Indicates the mechanical tilt of the antenna. Value range: 0 –359 Indicates the attenuation value of the current transmission angle. Horizontal Pattern
Parameter Figure area Angle
Description Indicates the horizontal or vertical beam figure of the antenna. Indicates the antenna angle.
Name
Manufacturer Gain Pattern Electrical Tilt
I. giving all angles and corresponding fading values. Antenna gain of this angle is represented by: Antenna Gain(θ) = Standard Gain – Attenuation(θ) The antenna angle is from 0° to 359°. The naming rule of the U-Net antenna consists of the following four parts: • Half power angle • Antenna gain • Electrical tilt • Application frequency Indicates the antenna manufacturer Indicate the antenna gain. Unit: dBi. Max Frequency and Min Frequency.Parameter
Description Indicates the antenna name.

The U-Net software does not establish a loss model for each piece of equipment. Click this button to set the properties of the selected site. Indicates the feeder type and will recall feeder table. Default value = 1 Indicates the transmit feeder length and the receive feeder length. Antenna Configuration
Parameter Dx.
Miscellaneous Losses
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. Indicates the miscellaneous transmit loss and the miscellaneous receive loss. Dy Equipment TMA Feeder Power Ratio Feeder Length
Description Indicate the offsets of coordinates X and Y of the current transmitter relative to the site location. User can simulate a remote transmitter by setting this parameter. Indicates the name of the site to which the current transmitter belongs.Parameter Name Site
Description Indicates the name of the current transmitter. such as combiner loss and power splitter loss. You can define additional losses.Equipment Allow user to fill in total loss or add individual component such as TMA separately Indicates the tower-mounted amplifier. The feeder loss is equal to the feeder loss per unit length multiplied by the total feeder length. Indicates the power allocation to the transmit equipment.
II.

A transmitter not yet activated does not participate in any calculation. If Activate is selected.
High Speed
Frequency Band
Indicates the Frequency Band used. Low Speed and Highway Click this button to view and modify the properties of the Advanced Parameters. Main Antenna Selectable between High Speed.
7. Neighborlist or Propagation Models related to this transceiver. the current transmitter is activated.III.6. General Define the radius of hexagongrid if it is used for new site design /Template Management/Properties]
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.7 Properties of a eNodeB Template
Path: [ I. LTE Cell Most of the critical parameters inside LTE cell table have been mentioned before and the content is shown here again.
Parameter Active
Description Indicates whether the current transmitter is activated.

LTE Cell Properties
Parameter Main Antenna Model 1st Sector Azimuth Indicates the transmitter antenna.II.
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.
Description
Indicates the azimuth of the first sector for a N sector site. The U-Net software evenly allocates the azimuth of the transmitter according to the azimuth of the first sector and the number of sectors of the eNodeB.

7 LTE Traffic Model Parameters
7.2 Environments
Path: [Explorer/Data/Traffic Parameters/Environment/Any environment type/ Properties] I. Indicates the user density in subscribers/km2. please see in the section below. and the methods for creating traffic maps.
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.1 Overview
This chapter describes how to set the properties of LTE Parameters folder.7.
7. For details on the setting of the mobility type in User Profiles.
Description Indicates the user type.7. the types of traffic maps.7. Indicates the mobility type corresponding to the user type. General
Parameter Name User Mobility Density Indicates the name of the environment type. please see in the section below. For details on the setting of the user type in User Profiles.

Indicates the duration of a call in seconds. Defined under Path: [Explorer/ Data/Traffic Parameters/ Terminals Profiles/Any Terminal type/ Properties]
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.
7. Please refer details on the setting of Service to Services section Indicates the terminal of the current service.4 Terminals
Path: [Explorer/Data/Traffic Parameters/Terminals Profiles/Any Terminal type/ Properties]
Parameter Name Reception Equipment
Description Indicates the name of the current terminal type.7. Please refer to Terminal section for setting detail Indicates the number of calls per hour.Parameter Name Service Terminal Calls/hour Duration UL Volume (Kbytes) DL Volume (Kbytes) Indicates the name of the user profile. Indicates the uplink user volume. Indicates the downlink user volume.
Description Indicates the service used by the current user. Indicates the type of equipment used by the current terminal.

the U-Net software calculates the transmit power of the terminal required to meet the current network QoS requirements. Indicates the terminal rate. If the required transmit power of the terminal is lower than this value. Indicates the maximum transmit power allowed for the current terminal. Indicates the antenna gain of the terminal. the U-Net software calculates the transmit power of the terminal required to meet the current network QoS requirements. the terminal is denied by the U-Net and limit the transmit power to Tx Max. If the transmit power of the terminal is greater than this value. Indicates the noise figure of the terminal. Indicates the receive loss of the terminal. Indicates the number of transmit antennas and the number of receive antennas at the terminal side. this parameter should be left blank.5 Mobility Types
Path: [Explorer/Data/Traffic Parameters/Mobility/Any Mobility type/ Properties]
Parameter Name Average Speed Indicates the name of the mobility type. the terminal transmits signals using this minimum transmit power.
Min Power
Max Power
Losses Noise Figure Model Gain Spatial Multiplex Support MIMO
7. Indicates the antenna technology used by the terminal. Description
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. Antenna Indicates the model of the terminal antenna. In general.Parameter
Description Indicates the minimum transmit power allowed for the current terminal. During the simulation. During the simulation.7.

2.4. Indicates the uplink or downlink maximum throughput per service Indicates the uplink or downlink minimum throughput of the service.
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Activity Factor
AMR Rate Max Throughput Min Throughput Average Throughput Transmission Efficiency IBER
Offset
Body loss
.7.95. Value range is from 0 to 1. which can be set to Voice or Data. Indicates the block error rate.9. Downlink transmission rate. which is the length added to an encapsulated packet during the transmission at the MAC or RLC layer. 5.
Description Indicates the service type. 1 represents the lowest priority. Value is 0 to 232. During the simulation. low-priority services are denied first when the cell resources reach the upper limit. 10.15. Downlink: downlink activation factor. Value range is 0. Downlink: fixed downlink overhead. Value range is 0 to 100. Indicates the uplink/downlink activation factor. 5. Indicates the fixed uplink/downlink overhead.75. Indicates the GBR service. Value range is from 0 to 1. Value range is 0. Indicates the priority of the current service. and 12. The unit is kbit/s. Indicates the body loss.2. 6. You can select the GBR service only after selecting Data. This parameter is used to calculate the application layer throughput. Indicates the rate of the CS services.7. which is usually 3 dB for voice services and not considered for data services. 7. This parameter is required for only the CS services. Uplink transmission rate.01 to 1.7. Value is 0 to 232.01 to 1. Indicates the uplink/downlink transmission rate. Indicates the average throughput requested by the service (using in creating a traffic map based on environment only). The values are 4.6 Services
Path: [Explorer/Data/Traffic Parameters/Services/LTE/Any Services type/ Properties]
Parameter Name Type GBR Priority Indicates the service name. 7. Uplink: uplink activation factor. Uplink: fixed uplink overhead.

I.
Path: [Explorer/Data/Traffic Parameters/Traffic Map]
Parameter Map based on Environments (Raster) Map based on User Profiles (vectors) Map based on Transceiver Coverage
Description Indicates the traffic map based on environments. Map based on Environments (Raster) Select the Environment type (DU/U/SU/RU) as discussed in previous section for a particular Polygon chosen to create Environment traffic map. Creating a Traffic Map Path: [Explorer/Data/Traffic Parameters/Traffic Map/New Map] Simply select the Map type and hit “Create Map” II. The Environment type will have the user type and their density distributed according to clutter weighting defined under Environment. Indicates the traffic map based on user profiles. Indicates the traffic map based on the coverage.7 Traffic Map
The U-Net software provides a total of three types of traffic maps.7.7.
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Map based on Transceiver Coverage Creating a Traffic Map The transceiver selected will be based on the Prediction Group chosen. A prediction group will only be created after a prediction has been carried out.Parameter User profile Mobility Density Indicates the user profile.
IV.
Description
Indicates the traffic density in subscribers/km2
Selecting Area (Polygon)
Parameter Name Density
Description Indicates the name of the area/polyon to which the vector area belongs. So only transceiver that had prediction information attached will be part of any prediction group. Indicates the mobility type. Indicates the traffic density of the vector area in subscribers/km2. Path for Predictions are: [Explorer/Operation/Predictions/] Setting the Properties of a Traffic Map Path: [Explorer/Geo/Traffic/Map based on Transmitters and Services & Map based on Transmitters and Services (#Users)/ Properties]
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If the total ratio is not equal to 100%.
The input here is the number of users for each service type
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. Indicate the distribution weight and indoor distribution ratio of the service or user for different clutter classes. the U-Net software automatically recalculates the ratios.Parameter Terminals (%) Mobility (%) Weight % Indoor
Description Indicate the distribution ratios of terminals and mobility of the service or user.

Parameter Prediction Group Tx_ID LTEFTP (UL) LTEFTP (DL) LTE (UL) VideoConferencing LTE (DL) VideoConferencing LTEVoIP (UL) LTEVoIP (DL) LTE (UL) WebBrowsing LTE (DL) WebBrowsing Selects a coverage prediction group
Description Indicates the transmitter name.8. Indicates the number of downlink users corresponding to the FTP service.8 Prediction and Simulation
7. Indicates the number of uplink users corresponding to the video conferencing service Indicates the number of downlink users corresponding to the video conferencing service Indicates the number of uplink users corresponding to the VoIP service Indicates the number of downlink users corresponding to the VoIP service Indicates the number of uplink users corresponding to the Web browsing service Indicates the number of downlink users corresponding to the Web browsing service
7. which is set in the properties of a single transmitter in the Transmitters folder.1 Predictions
Path: [Explorer/Operations/Predictions/Properties] User can then select the type of prediction required.
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. Indicates the number of uplink users corresponding to the FTP service.

General information
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In general. the probability that the receive signal strength is stronger than the specified threshold at the edge of a cell Indicates whether penetration loss is considered in the calculation Indicates whether frequency offset is considered in the calculation. Loading of Neighbour cells. the default precision (50m) is used for the prediction. ie. If RS Shifting is selected during the prediction of the counter DL RS SINR. This parameter is valid during the prediction of the counters Handover Area and Overlapping Zones Indicates the handover threshold of inter-frequency cells. only the interference on the RS is taken into consideration. Indicates the handover threshold of intra-frequency cells. it indicates that the interference is calculated according to values of cell PCIs after the modulo operation is performed. If cell PCIs are not planned. If the precision is not specified for a prediction.Resolution
Indicates the resolution of the prediction map.
Intra-Frequency Handover (dB) Inter-Frequency Handover (dB) Polygon Neighbour load With Shadow Cell Edge Coverage Probability Indoor Coverage
RS Shifting
II. Advanced
Frequency Name Channel Index
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Indicates the name of a frequency band Indicates the ARFCN corresponding to a frequency band
. This parameter is valid during the prediction of the counters Handover Area and Overlapping Zones. Please refer to Load Setting section Indicates whether shadow fading is considered in the calculation Indicates the probability of cell edge coverage. Otherwise. the prediction precision is the same as the map precision. the precision specified for the prediction is used. Indicates the area calculated in coverage prediction.

No calculation is performed if the value of the parameter in the middle of the equality is lower than this value.III. Indicates a service type Indicates a terminal type Indicates a mobility type Indicates the interference threshold
IV. Indicates the method used for the current prediction. Indicates the upper limit of the predicted value. No calculation is performed if the value of the parameter in the middle of the equality is higher than this value. Condition
Parameter Parameter on the left of the inequality Parameter in the middle of the inequality Parameter on the right of the inequality Service Terminal Mobility Interferer Reception Threshold (dBm)
Description Indicates the lower limit of the predicted value. Viewing Prediction Results User can review the results both statistically or in table format
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Once it is ready. Indicates a calculation area to be selected.
Parameter Global Scaling Factor Select Traffic Maps Select Calculate Area
Description Indicates the scaling factor of user number.
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. Planner can adjust the “Source Traffic” table as below. Number of users = Size x User density x Scaling factor of user number Indicates a traffic map to be selected. Setting Monte Carlo method is used by U-Net for traffic distribution.
Traffic Map needs to be created prior to running simulations.I.

which is use for checking whether a network is converged.
Number of TTI
Site Corr UL IOT Convergence Threshold UL Load Convergence Threshold (%) DL Load Convergence Threshold (%) UL Throughput Convergence Threshold (%) DL Throughput Convergence Threshold (%) TTI Bundling VMIMO IRC HARQ Fix User Position
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. which is used for checking whether a network is converged. configuration of “Advance Parameters” Table is also required
Parameter
Description Indicates the number of transmission time intervals (TTIs) within a snapshot. U-Net adopts the semi-dynamic simulation to obtain the instantaneous network information as per TTI within a snapshot. Indicates the uplink IoT convergence threshold. which is used for checking whether a network is converged. A larger TTI count allow better reflection of scheduling. therefore increases the precision of simulation results but requires longer calculation period. Indicates the downlink throughput convergence threshold. Indicates whether the virtual multiple-input and multiple-output (VMIMO) is considered. which is used for checking whether a network is converged. Indicates whether the location of user is fixed. Indicates the shadow fading factor on the base station side.Finally. Indicates whether TTI Bundling is considered. Indicates the uplink load convergence threshold. Indicates the uplink throughput convergence threshold. Indicates the downlink load convergence threshold. Indicates whether interference rejection combining (IRC) is considered. Indicates whether hybrid automatic repeat request (HARQ) gain is considered. which is used for checking whether a network is converged.

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Individual users’ simulation results can also be seen by pointing the mouse on top of the user locations within the Simulation
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Simulation Results Various results can be obtained from the simulation results. and throughput results. Planners can then see the average value as well as the distributions of these results graphically.
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.II. IoT. including cell loading.

9. After you specify the transmitter.2 Reception
Parameter Display area
Description Indicates the names and signal strength of all the cells available for the terminal at the Cursor location
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. Path: Click or on tool bar “Window – Point Analysis Tool”
7.
Parameter Transmitter Path Loss/DL RSRP Cell Edge Coverage Probability
Description Indicates the transmitter. User enter the required value and Margin needed will be displayed
7.7. Choose to display either the path loss or the DL RSRP at the Cursor.9 Point Analysis Tool
This section describes how to use the point analysis window and explains the relevant parameters.1 Profile
Purpose of this window is to display the terrain profile in relation to signal loss. you can view the profile of the path from a point on the map to this transmitter.9.

7. whose simulation results are used to simulate the current analysis environment. moving speed.the received signal strength and Clutter class
7.4 Result
This page displays the coordinates and altitude of the current cursor location.9. and the permitted access carrier of the terminal represented by . service.9.3 Signal Analysis
Parameter Simulation group Terminal or Mobility or Service
Description Indicates a simulation or a group of simulations.10 RF Cell Planning Optimization
U-net also offer radio network planners an network planning optimization tool.7.
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. Indicate the type of the terminal. the class of clutter in the position where the terminal is located as well as list of cells from which signals can be received.

The greater the number of iterations is. Table value – General Tab
Parameter Name Analysis Area Simulation Area Max Iteration Count Resolution RSRP Target Ratio Indicates the RF auto-planning area Indicates the simulation area of RF auto-planning (this area must contain the analysis area.000 Indicates the percentage of the downlink RSRP that reaches the specified threshold in the selected calculation area.) Indicates the maximum number of iterations. Value range is from 0 to 32.768. Indicates the precision in calculation.Path: [Explorer/Operation/LTE Cell Planning/]
Optimization selection steps
I. Value range is from 0 to 100. the more accurate the planning result is but longer time the calculation takes.Value range is from 0 to 10. Description Indicates the name of an RF planning group
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Value range is from 0 to 32. Indicates the step length at which the reference signal is adjusted.
7. Value range is from 0 to 360.768. Value range is from 10 to 40. that is. the more accurate the planning result is. Value range is from 0 to 360.768. In U-Net. the total number of individuals in a population. Value range is from 0 to 32. Value range is from -360 to 0.
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. Value range is from 0 to 90. Value range is from 0 to 1. Value range is from -32. Individuals of Population Size are calculated in each iteration and the greater the number of individuals.11 U-Net Planning Case
U-Net is widely applied in global LTE planning projects by RNP engineers.
Population Size
Antenna Tilt Max or Min Value Antenna Tilt Max Range Antenna Tilt Min Range Tilt Step Size Reference Power Max or Min (dBm) Maximum Range Minimum Range Power Step Size Antenna Azimuth Max Range Antenna Azimuth Min Range Antenna Azimuth Step Size
7. The value range is from -180 to 0. Indicates the step length at which the azimuth is adjusted. RS SINR Fitness Weight + RSRP Fitness Weight = 1 Indicates the weight of the RS SINR performance counter of a cell.768 to 32.The value range is from 0 to 180. Here is one case presented as reference. Value range is from -90 to 90. Urban and Suburban. Main morphologies include Dense Urban. an individual represents the configuration combination of the RF parameters related to all the cells in a calculation area. Indicates whether to perform the RF auto-planning immediately
II.11. Indicates the maximum/minimum transmit power of the reference signal. Control Parameter
Parameter
Description Indicates the size of a population. RS SINR Fitness Weight + RSRP Fitness Weight = 1 Indicates the percentage of the downlink RS SINR that reaches the specified threshold in the selected calculation area.768 Indicates the minimum adjustment range of the reference signal. Indicates the minimum adjustment range of the azimuth. Indicates the maximum/minimum downtilt angle.768 to 0. Value range is from -32. Indicates the step length at which the downtilt angle is adjusted. Value range is from 0 to 1. Indicates the maximum adjustment range of the reference signal. Indicates the maximum adjustment range of the downtilt angle. The planning area is about 30 square km and shown as the red broken line polygon.Parameter RSRP FitnessWeight RS SINR Fitness Weight RS SINR Target Ratio Calculate Now
Description Indicates the weight of the RSRP performance counter of a cell. but the longer time the calculation takes. Indicates the minimum adjustment range of the downtilt angle. Indicates the maximum adjustment range of the azimuth.1 Overview of Planning Area
The clutter information and planning target area of City X are presented as below.

Retainability.1 KPI Measurement Methodology
The KPIs are formulated to measure the network performance in terms of Accessibility. preliminary acceptance and final acceptance. providing a wide range of network KPIs to reflect network factors that are relative to the service quality.8 LTE Network Key Performance Indicators
8. Mobility. Integrity. Latency. using industry standards as reference to define network counters and KPIs. and Integrity. Accessibility. and Subscriber perceived quality. Retainability.
KPI Architecture
The above KPI classification fully considers the customer experience and focuses on the Quality of Experience. which are.2 KPI Acceptance Procedure
LTE network KPI acceptance procedure for the two phases.
8. Mobility.
LTE KPI Acceptance Procedure
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. The KPI architecture is shown in the following figure. are recommended as shown below. LTE KPIs are mainly classified into 5 classes.

the final acceptance of the whole network performance on the basis of statistics will be implemented. the KPI values of statistics probably might not be same with those in drive test due to different calculations and considerations. but the actual sites number of per cluster should be flexible to allow a faster rollout and acceptance. However. and this analysis and measurement are on the basis of cluster which constitutes a group of sites (20-40 sites). such as Call setup success rate. We recommend that only one cluster (named pilot cluster) is selected for the evaluation and acceptance for the Service KPIs. Statistics KPIs are not proposed and measured at this stage as the traffic is insufficient. if possible.
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. statistics will not eligible statistical result without enough samples. (2) Drive Test Route Selection For cluster optimization. etc. Whereas. e. Call Drop Rate. should be performed on the Drive Test (DT) routes in rollout clusters. no necessary for repeating the measurement in all clusters Based on the above reasons.g. planning and optimization capabilities. which is determined by the radio network environment. coverage. major roads. tourist attractions and railway stations. (1) Cluster Optimization Performing optimization/acceptance per Cluster is recommended.. etc. Cluster means a group of sites (Normally 20-40 sites) which are geographically neighbor and all the eNodeBs of this test cluster should be integrated and on air. neighboring relations. After on-going optimization while the traffic keeps increasing after commercial launch. the planning of the test route shall consider the handover performance. throughput. configuration and parameter setting. In general the test routes shall be planned according to the following criteria: (a) All sectors of each site in the cluster should be covered by the drive route. (b) Routes shall pass through Key business centers. Handover Success Rate. mainly determined by product performance.During the phase of preliminary acceptance before commercial launch. KPIs will be derived from the drive test analysis and stationary measurements. Service KPIs are the KPIs that are not subject to be effected by cluster tuning and optimization activities. for Network KPIs. ping delay. along with surrounding neighbor cells. the Service KPIs’ test is suggested to be performed by Stationary Test (ST) in the area with good RF conditions and close to the cell in order to eliminate the affect of poor RF or non-equipment factor and the test is proposed to be implemented under the condition of one serving cell.
8.3 Service KPIs and Network KPIs
The Field Test KPIs into two categories: Service KPIs and Network KPIs.4 Cluster and Test Route
The following contents present recommendation for Cluster Optimization and the selection of Drive Test Route for this project.
8. shopping centers.

(1) Preliminary Acceptance For Preliminary Acceptance (before the commercial launch).
KPI Classes Accessibility Retainability Mobility Indicators RRC Connection Establishment Success Rate ERAB Establishment Success Rate Call Drop Rate Handover Success Rate (Intra-system) Proposed KPIs for Final Acceptance Test Method Stats. Optional) For Final Acceptance (after the commercial launch). the following KPIs are suggested for Preliminary Acceptance and Final Acceptance separately. Stats. Stats. Different measurement methods and KPI categories shall be taken into consideration so as to match the following two acceptance phases. The main purpose of Preliminary Acceptance is to verify whether the optimized cluster achieves the coverage and performance requirements or not. so the Field Test (Drive Test and Stationary Test) KPIs are recommended for this phase.
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.8.
KPI Classes Accessibility Retainability Throughput Delay/Latency Mobility Indicator E-RAB Establishment Success Rate Call Drop Rate DL Single User Throughput UL Single User Throughput Round Trip Time (Ping 32Bytes) Handover Success Rate (Intra-system) Proposed KPIs for Preliminary Acceptance Test Method Drive test Drive test Stationary Stationary Stationary Drive test
8.6 Proposed KPIs for Final Acceptance (Stability Acceptance. low traffic (even empty) is not able to produce sufficient traffic data to evaluate the correlative Statistics KPIs.5 Proposed Key Performance Indicators
There are two types of methods for KPIs’ measurement: Field Test and Statistic Collection. Optional)
The following table lists the proposed KPIs for Final Acceptance. (2) Final Acceptance (Stability Acceptance. statistics collection method could be introduced under the condition that a minimum amount of traffic per site at the Busy Hour is reached (the sufficient data are available). Based on worldwide experiences of LTE commercial networks.
Proposed KPIs for Preliminary Acceptance
The following table lists the proposed KPIs for Preliminary Acceptance. Stats.

The purpose of the checklist is to ensure all the major aspects are considered either from our intelligence or with customer input. Spectrum only available within 100km from City centre) • Will the entire network be running on the same frequency spectrum (e.2. will customer buy more spectrum in same band. radio planning engineers should have a good understanding on the technological background.6G but countryside is 800) Too often proposals are based on wrong assumptions on spectrum and the available bandwidth that will be used for new network deployment which results in a significant cost and work implications.1 Introduction
By now. Further issues need clarifications include • Spectrum availability and timeframe e.2 Actual Frequency Band Allocation for LTE
Similar to spectrum bandwidth availability. 15MHz or 20MHz bandwidth.g.2 Checklist Items Consideration
Radio planning engineers are highly recommended to review the following checklist items in full and confirm the detail of all these items BEFORE committing to any network site count to begin to perform any network simulation
9. it is generally true downtown area would require higher bandwidth (15MHz or 20MHz) due to higher traffic requirement while rural and/or suburban area may only require smaller bandwidth (10MHz). the final network plan created will sure be more customer relevant and less rework will be required.
9. However. swapping customer current spectrum to another band) • Any spectrum licenses restrictions (e. radio planners need to know which band is to be given for their network. This chapter will go through the required information step by step from a practical implementation perspective to highlight the approach needed for both radio engineers in deciding on the strategy required for LTE network planning.
9.9 Network Planning Checklist
9.g. limitations and considerations required for the planning of a LTE network. With all these information on hand. • Will customer need to perform migration or refarming of 2G/3G technologies first before spectrum is available for LTE • Any government plan for Spectrum recovery (e. The same five questions/issues raised in “Understanding Customer Spectrum Bandwidth Availability” also need to be
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. 10MHz. different band.g. City is 2.g.2. The final frequency band granted will have a significant impact on site count and hence overall project cost due to the propagation and pathloss characteristics of different frequency bands.1 Understanding Customer Spectrum Bandwidth Availability
The purpose of detail planning is to determine a solid radio network design for possible deployment so radio engineer should not be using detail planning as a mean to determine or compare the network capacity offering between 5MHz.

RRU. As a result. users are likely to be of lower usage and of higher speed so maximizing coverage through site antenna height or higher terrain is more important. radio planning engineers need to have a good understanding of where customer traffic will be in order to allocate an appropriate distribution of base stations. coupler or splitter addition) to enable co-siting with existing technology (CDMA/GSM/UMTS) • Changes in Hardware (e. This allocation can be affected by such factors as indoor
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. Currently. high subscriber density and high usage is expected for dense urban and city area. In general. no detail network design activities should begin. require GSM planning).e. the following items will need to be considered carefully prior to detail network design: • Any co-location with Existing Technology (2G/3G)? • Guard Band in place already? If not. jumper cable. there is also a big push in Europe for white spot (rural) wireless DSL coverage in Europe DD spectrum based on LTE.clarified here if it has not be done so before any detail planning activities are to begin. introducing TFR to improve GSM efficiency first. marketing strategies and even management preferences to showcase their technological leadership or not. high subscriber density area are most likely made up of users with low mobility so the emphasis on site placement for dense urban is more critical and it is important to be closer to users in high traffic area. it is recommended until a clear vision is obtained from customer for all 3 questions listed above. antennae change. TMA) which will lead to path loss changes. On the other hand. hence it is normal to have more site count being allocated to dense urban/urban environment. In case where LTE is to be introduced after spectrum refarming. growth forecast. Not necessary LTE specific but will be required by 2G/3G e. different customers will have different focus on traffic requirement. This is mainly because the final site count is more likely to be determined by coverage requirement and the capacity offered by the network is the product of site count x capacity per site.g. • Extra workload requirement due to refarming which may have human resources impact (e.g.g. the final capacity offer by the network will be different due to the coverage requirement. It is also worth noting here although the bits/Hz value will not change with different frequency band (i. Therefore. In summary.4 Location of Customer Coverage Requirement
It is critical to have the proposed LTE site locations correspond to where it can best serve the designated traffic area and traffic type. in rural and highway condition.
9. per cell capacity is bandwidth not frequency band dependent). answers to these questions are highly variable and every network will be different due to their current capacity status.2.3 Frequency Band Refarming Requirement for LTE
Some of the most popular questions from customer these days are • How they can perform refarming? • When is the best time? • How much spectrum do they need? For radio planners.2. Guard band spectrum availability? • Additional passive equipment/path loss introduced due to possible equipment swap out (e. In developed markets.
9.g.

downtown area will require higher resolution while rural town can accept data of a lower resolution nature. it will be inappropriate to design a radio network with solid coverage everywhere (suburban/rural alike) where customer do not appreciate the value or return on their investment. it is NOT a good practice to rely on the external eNodeBs to provide coverage inside the tunnel. it is also important to ensure the clutter data is not shifted from the real structural location. 50m.g. In both situations. Clutter resolution comes as 10m. Besides data resolution.
9.2. In general. • It is unwise to place an InterRAT border in a heavily congested area. • It is also not recommended to place any InterRAT border along interRNC/BSC or inter PLMN border area.5 Highway and Tunnel Coverage Requirement
Most Operators will require good coverage along major highway and major tunnels due to the strategic visibility of services. This is particularly important before designing any network that requires commitment on KPIs later. understanding the current status of the underlying network from both a coverage and performance perspective is critical in finalizing the LTE network design and capacity planning.2.7 Terrain and Clutter Database Availability and Accuracy
It may not appear to be important but the resolution and accuracy of terrain and clutter information will have a BIG influence on the reliability of the final network design. it is not appropriate to locate an InterRAT border in location where the existing 3G or 2G network is of poor coverage. this means either smaller bandwidth. there will be a need for InterRAT handover either due to coverage hole within the LTE network or on the fringe of the LTE network to area beyond its coverage. In order to make these InterRAT boundary decision intelligently. Google earth (which is normally 3
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. 25m. Hence.
9. It is very worthwhile to valid the clutter information against other sources of information e. • Similarly. If customer focus is just in covering dense urban area. it is reasonable to request traffic loading and performance information from the customer regarding the existing network both within and on the edge of the proposed LTE network
9. In any Greenfield LTE deployment.6 Evaluate Existing Network Condition for InterRAT
Radio planning engineers need to understand the existing customer’s network configuration as well as its footprint. • Try to locate LTE InterRAT border in area where customer network is offering good throughput to reduce the level of future customer complaint. One major problem for this type of coverage is the feasibility of installation due to for example space and air conditioning restrictions inside tunnel or location restrictions along major highway so Radio planner also need to ensure the appropriate type of eNodeB is chosen. Another important factor is when the database was made available and when was the latest update made. In LTE. traffic likely to be high speed but low volume so smaller capacity provisioning is acceptable. 100m and beyond depending on the price paid as well as the location of the clutter.2. For instance. For example. small transmit power or even less MIMO complexity as long as coverage is fine.penetration margin and slow fading margin in the link budget.

Sometimes. there is always a need of indoor microcell and customer is normally quite willingness to pay for the extra coverage.2.11 Call Model and SmartPhone Penetration Growth Considerations
The arrival of Smartphone has introduced a whole new trend in data applications and hence resource usage condition.g. Canada and Australia. final site count will also be affected as it would be unwise to assume high data traffic usage uniformly across the entire network. The final requirement of site count will thereby be directly impacted. customer may have difficulties in accessing certain buildings or shopping malls so these areas may need to be covered by outdoor eNodeBs which will increase the penetration requirement. major pedestrian walkways. There is now a much bigger data requirement especially in short and bursting traffic.
9. As a result. Government legislation to improve rural/
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. the edge throughput requirement is also a result of special government legislation on Operator e. PF scheduling is preferred but Max C/I scheduling will give the best throughput for a network with solid coverage.10 Cell Edge Throughput Requirement
The final requirement of Uplink and Downlink throughput requirement at cell edge has to come from customer and is directly related to their pricing as well as branding.
9.to 6 months late) to ensure critical structures have been included. major stadium and other high profile locations) are covered? Do they have dedicated cell coverage? • How much penetration margin is provided for indoor coverage? Indoor user will be a major factor for interference generation to other users due to the higher power requirement. It is likely high data usage traffic be concentrated around dense urban and urban area while Rural and Highway area will consist of lower than average data user.9 Indoor Coverage Requirement
Customer coverage expectation will have a direct impact on link budget considerations for both indoor penetration requirement and standard deviation.g.
9.2. Nevertheless.2.
9. Depending on the network morphologies weighting. subway stations and airports. at important indoor locations such as lobbies of major hotels. Other important questions to be considered before finalizing the network plan are • How much spare capacity the network has to tackle the growth and change in subscriber’s usage without adding extra equipment? • How well data hot spots (e.g. • Any major driver for surprise usage increase in the near future? (e.8 Scheduler Selection
Radio design engineer can choose between different data transmission schedulers in the OSS database depending on the likely radio performance of the network. big shopping mall. On the other hand. Normally. some networks are seeing single smart-phone user consuming up to 14 times network resources normally consumed by traditional non smart phone user. By assigning appropriate data user model inside U-net. popular sport stadium. different usage behavior should be simulated accordingly. white spot coverage in European countries like Germany as well as rural coverage in US.2.

In general. combiners. Due the close vicinity to traditional microwave frequencies. splitters and jumper cables) needs to be included in the prediction design to ensure all the extra combining loss are included due to equipment co-siting. indoor DAS (distributed antenna system) may contribute to interference problem particularly on the uplink due to PIM related inter-modulation. Wideband repeaters operating in the same or even adjacent band to the LTE networks may generate unwelcomed interference.6G may also be subjected to interference either from standard microwave. no additional loss will be incurred. standard isolation would be required if equipment from different vendors are to be combined. Finally. Existing radio networks are also likely to have additional downtilt for coverage control purposes so independent tilt for Greenfield LTE network may help to reduce the final site count required. While use of separate and/or new antenna may incur additional project cost.2. Hence.
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. Hence.suburban usage. this may come at the expense of limitation in tilting flexibility. if the LTE network is to be overlay on other vendor’s network within the same frequency band. satellite transmission or MMDS/LMDS networks. tunnels and sporting stadium. Conversely. home DSL replacement package.2. New multiband antennae now offered by Huawei Agisson can provide independent electrical tilt for different band which may be useful for some situations. Please refer to previous discussion in Chapter 5 for guard band. shutting down of existing data network and migrating users to new LTE networks)
9. over drive of input RF power as well as impedance mismatch between components.12 Base Station Antenna and Other Co-siting Equipment Selection
New LTE network is likely to be overlaying with customer’s existing radio networks. LTE networks at 2. addition loss (e. filtering as well as vertical/horizontal separation information. These two factors could lead to extra guard band and worst case full retune requirement for protection purposes. If SingleRAN solution is already in place and new LTE network is built on frequency band covered by existing antennae. radio engineers need to ensure project team or customer can provide appropriate installation feasibility for such locations.
9. However. installation of new antennae in certain locations may not be possible due to local authority restriction. for example: inside shared antenna system in major shopping malls.13 Interference Protection and Isolation Requirement
Similar to any radio network. certain network requirements may demand new antennae altogether due to different network coverage requirement. engineers should not rely on tunnel coverage to be provided by radio signals coming from the base station located outside the tunnel premises. radio planners need to evaluate the benefit of having this tilting and orientation flexibility carefully on a site by site basis. On the other hand. antenna selection would be a critical factor in the new LTE radio network design.3G to 2. Frequency band of the new LTE network will also be a critical factor in antenna selection.g. However. In addition. 700/800MHz digital dividend spectrum could be subjected to interference signals coming from big television broadcasting towers.

RRU power and guard band/spectrum requirement).
9. ideally. beams will be at least a few wavelength apart but the arrival of higher transmit/receive order antenna may well change this situation in the future. All these considerations will affect the selection of network components involved (e. beam forming is very similar to the diversity transmission.2. However. radio engineers should choose a spectrum that is relatively clean in both the uplink and downlink for new LTE systems deployment. Normally.2.2.g.16 MIMO and Beam Forming Implementation
The number of antenna deployed per cell will have an immediate impact on the coverage and capacity offered by diversity based technology like LTE. Although external interference sometimes could be unavoidable due to various reasons.
9.5dB) vs Macro RFU (3dB). due to installation limitation.17 Cyclic Prefix Planning
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. radio engineers need to remember the addition of new antennae may incur extra CAPEX and OPEX cost on the operator due to extra mounting pole requirement so prior customer discussion is recommended. site drawing)
9. the main difference being that in beam forming one typically considers a physical antenna beam being constructed towards the UE. antenna orientation and tilt may need to be adjusted to avoid interference from external sources and existing customer network configuration may give hints in this direction. most FDD based Operators will likely to be focusing on existing spectrum (850/900/1800MHz) refarming while WiMAX Operators will have major concern on co-existence between WiMAX and LTE TDD. However. the total path loss will also be different so radio engineers need to discuss with customer in detail on their plan and preference to ensure the discussion results are reflected in the detail network design plan. Careful planning of location update border and coverage control remains two of the most important techniques in resolving this problem. it is important the benefit of applying such products is reflected in our design proposal and link budget estimation.g.15 Network and Spectrum Evolution Consideration
Different Operators may have different network evolution considerations. there is a 2. As a major application for LTE TDD.14 Radio Related Equipment Selection
With the introduction of new Remote radio head technology. Depending on the chosen direction. For instance. filter bandwidth. For instance. So for best result.At certain cell site sectors.5dB reduction in cable loss in using DBS RRU (0.
9. beam forming requires closely spaced antennae and this is unlike the MIMO diversity schemes which require at least a few wavelength antenna spacing. interference increase due to traffic loading is always an important consideration especially when subscriber number increases. Finally. Radio engineers also need to understand the current configuration of customer sites so the realistic cable and/or combiner loss are reflected in their coverage design. a cable length of 30m is assumed but this definitely needs to be reviewed during the design stage on a site by site basis based on customer information (e.2.

On the other hand. number of signal bars). Radio engineers are recommended to determine the traffic ratio between downlink and uplink from the customer’s current network to assist in the selection of appropriate slot assignment ratio. The different combination will have an impact on both the coverage and capacity availability especially when there is an extended range requirement.19 UE Distribution and Channel Model : Pedestrian vs High Mobility
The impact of user distribution (pedestrian oriented vs high mobility focus) needs to be reflected in the channel model chosen for link budget estimation. Transmission expansion based on microwave could be lengthy from a time perspective due to various technical and spectrum regulations so radio planners should report their requirement as soon as possible. there are seven Downlink vs Uplink assignment ration as well as nine Uplink/Downlink Pilot Time Slot vs Guard Band configuration available for radio planner’s selection. Requirement of extended cell can also be determined via customer discussion and current network coverage review to minimize provisioning of guard band in LTE TDD network.2.
9.g. Result of backhaul congestion will be slower user throughput. This is because power control works much more efficiently in low mobility environment and its gain diminishes as the speed of mobility increases.Radio engineer should also discuss with customer to ensure any sites needing extended coverage are addressed by using the Long CP configuration as discussed in Chapter 3 and 6. Although the expansion of backhaul capacity will normally occur in conjunction with LTE access network rollout. the perception of customer coverage is likely to be dictated by the “coverage” shown by UEs (e. capability and capacity is made.
9. using the wrong incorrect (higher mobility) channel models will have a higher demand on capacity and throughput estimation. Shanghai or Singapore.2. for more mobility oriented cities in Western Europe. it is still essential to ensure no commitment of radio access throughput beyond backhaul latency. If the target network is a dense metropolis like Hong Kong.20 TDD Specific Uplink and Downlink Configuration
Due to the spectrum sharing and time division nature of TDD. An appropriate buffer needs to be provisioned by the transmission planners as there will be extra loading due to S1/X2 interfaces as described in Chapter 6. possible drop call and QoS/QoE degradation.21 Power Boosting Configuration
Similar to most wireless systems. using a more pedestrian oriented channel model will most likely result in an under-estimation of equipment requirement.2.18 Understanding of Current Transmission Backhaul Network Capability
Radio planners should regularly report and remind core and transmission network designers about the LTE access network transmission capacity requirement based on customer edge throughput and traffic requirement. North America and Australia/New Zealand. appropriate proportioning between mobile and pedestrian users can also be configured in U-Net Simulations using the correct channel mode under each of the Environment entries. a higher power boosting
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. On the other hand.
9.2. at initial LTE network launch when loading is low. Hence. radio engineers should observe the local condition and make appropriate adjustment in their radio plan.
9. Hence.

factor will help to improve coverage perception and reduce cell site count as RSRP is always a major requirement from customer. the more RE will be consumed • More new sites are likely to be added to enhance coverage as well as capacity so Power boosting will indeed have a negative impact on coverage control in this situation. once network traffic grows steadily. However.
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. there will be a need to scale back power boosting as • Power Boosting consumes extra RE that could have been used for traffic • The higher the MIMO order.

2.2 Antenna Classification
There are dozens of antenna types and variations of each. and vice versa. Electrical energy is fed to the antenna via a transmission line. Types of directive antennas are the Yagi. the parabolic dish.3 Main Specifications of Antenna
The technical specifications of antenna include: • Work band • Gain • Polarization mod • Beam width • Preset down tilt • Down tilt mode • Adjustable range of down tilt • Front-to-rear ratio • Side lobe suppression ratio • Zero point filling • Echo loss
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. the biquad. the helicoidal. triple-band antennas. the patch antenna. etc
10. and many others. The beam can be as wide as 180 degrees. sector or directive. dual-band antennas. The most popular types of omnidirectional antennas are the dipole and the ground plane.
10.1 Overview
Antenna is a device which converts an electric wave guided by a conductor into a free-space.10 Appendix: RF Antenna Systems
10. The wave guided by the line is radiated into space by the antenna. wide-band antennas. The type of antenna selected for use depends on the propagation characteristics required. the horn.2. Sectorial antennas radiate primarily in a specific area. or as narrow as 60 degrees. Directional or directive antennas are antennas in which the beamwidth is much narrower than in sector antennas.
10.2 Directivity
Antennas can be omnidirectional. a conductor which passes electrical energy from one point to another.
10. A matching device is usually required to ease the abrupt transition between the guided and the free wave. They have the highest gain and therefore used for long distance coverage.1 Frequency
Antennas can be classified as single-band antennas (narrow-band antennas). Omni-directional antennas radiate roughly the same pattern all around the antenna in a complete 360° pattern. unguided electromagnetic wave.

The d in dBd means dipole. Band 39) • 2300-2700MHz (TDD Band 38/40 and FDD 2.
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. 2100MHz. N or DIN) • Wind load
10. Huawei Agisson is offering antenna product of the following frequency band: • 806-960MHz (FDD 850MHz. AWS and TDD Band 33-37.2 Antenna Gain
The antenna is a passive device. Gain is a key index for antenna.3.1 Work Band
It is the work band of LTE system.6G) • 824-960/1710-2180MHz (Dual Band) • 2300-2700/2300-2700MHz (for 4T4R MIMO) The only major band not covered by Huawei Agisson is 700MHz band used mainly for US LTE networks. The i in dBi means isotropic. It can neither strengthen the signal nor transmit signal by itself.
10.• Power capacity • Impedance • Third order intermodulation The mechanical specifications of antenna include: • Dimensions • Weight • Number Input ports • Port connector type (e. There are usually two units for antenna gain: dBi and dBd. The relationship between the two units is as the following equation: 0 dBd = 2. • dBd: the capability of concentrating power by actual directional antenna (including omnidirectional) compared with half-wave dipole antenna.g. It concentrates the power to a direction by changing the combination of oscillators and changing the feeder mode. standing for the capability of concentrating the power to a direction. 900MHz) • 1710-2170MHz (FDD 1800MHz.3.15 dBi • dBi: the capability of concentrating power by actual directional antenna (including omnidirectional) compared with the isotropic antenna.

Figure 6-2 shows the horizontal and vertical patterns of directional antenna.3.
10. There are other special directional antennas. similar to the interferometric effect of optics in principium. The antenna pattern is a cubic figure. • If the pattern is represented by phase. such as heart-shaped antenna and 8-shaped antenna. This is the surface pattern. In mobile communication. The lobes near the main lobe with the second highest power are the first side lobes. it is called phase pattern. The lobes of various shapes and zero points form. There are also omnidirectional antenna pattern and directional antenna pattern. The directionality of antenna lies in the ranking of oscillators and the variety of feeder phase.
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. The second side lobes are those with the third highest power…. • If the pattern is represented by power density. it is called power pattern. horizontal and vertical beamwidth. the power in some directions is strengthened while the power in some directions is weakened. The surface pattern includes vertical pattern and horizontal pattern. As a result. • If the pattern is represented by radiation field strength. it is called field strength pattern.3 Antenna Pattern
The pattern is the electromagnetic field of antenna radiation distributed by coordinate along fixed distance.Figure 10-1 Relation between dBi and dBd
The antenna gain is relevant to the number of oscillator units. The lobe with the highest power is the main lobe. The directional antenna produces a rear lobe. usually represented by two patterns which are vertical to each other in a main plane. the power pattern is the most common.

the horizontal beamwidth is in inverse proportion to the vertical beamwidth. and 33°.5°. the gain is 11 dBi. • β: the vertical beamwidth in the unit of dBi. According to the previous formula. if you have known the antenna gain and horizontal. the actual vertical beamwidth of omnidirectional antenna is
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. with their relation as below:
Wherein.Figure 10-2 Horizontal and vertical patterns of directional antenna
10.3. 7°.5 Relation between Beamwidth and Gain
The antenna concentrates power.
10. • Ga: the antenna gain in the unit of dBi. For example. The common horizontal beamwidth of eNodeB antennas includes 360°. for an omnidirectional antenna. the horizontal beamwidth is 360°. 10°. 60°. You can usually reduce the horizontal beamwidth to strengthen the power of a direction.3. When the antenna gain is fixed. • θ: the horizontal beamwidth in the unit of dBi. 90°. The common vertical beamwidth of eNodeB antennas includes 6.4 Beamwidth
The beamwidth is also called the half power beamwidth. 65°. you can calculate the vertical beamwidth. The horizontal beamwidth and vertical beamwidth is the beamwidth between two points where the power is lower 50% (3 dB) than the maximum radiation power. 13°. It strengthens the power of a direction while reducing the power of other directions. and 16°. so the vertical beamwidth is calculated as below:
Due to the deficiency of design and manufacturing process. including horizontal beamwidth and vertical beamwidth.

Therefore.
10. the better the antenna is designed.
10. the higher the gain is and the larger the aperture of antenna (the effective receiving area) is. The less difference between the two beamwidth. the difference between the level of side lobe and the maximum beam in the range of rear 180°±30°.6 Front-to-rear Ratio
It is the ratio of signal radiation strength of main lobe to that of rear lobe. The front-to-rear ratio of common antennas is between 18 dB and 45 dB.7 Upper Side Lobe Suppression
In a cellular network. In addition. The larger the number of oscillators.usually smaller than the calculated result. the antenna length will double. you need lower the upper side lobe that radiates neighbor cells and improve
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. and horizontal beamwidth
According to the figure above. for shaped-beam antenna. a positive value.3. the antenna gain depends on the number of oscillators. vertical beamwidth. For an omnidirectional antenna.3. if the antenna gain increases by 3 dB. the vertical beamwidth and horizontal beamwidth are usually large. when the antenna gain is low.
Figure 10-3 Relation among antenna gain. to improve the efficiency of frequency reuse and reduce the intra-frequency interference with neighbor cells. the vertical beamwidth and horizontal beamwidth are usually small. When the antenna gain is high. the antenna gain is usually within 11 dBi.

If unspecified. Assume that: • ZA: input impedance of antenna • Z0: nominal characteristic impedance
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. This is invalid to the antennas of macro cell eNodeB.
10. the polarization wave is elliptical polarization wave. and adjustable electrical down tilt (RET antenna) as below: • Mechanical down tilt: you adjust the mechanical down tilt by lowering the support.8 Polarization Mode
The polarization is a radiation feature for indicating the vector special direction of field strength of electromagnetic wave. preset electrical down tilt. and they are all linear polarization.3. the spatial direction of electric field vector usually serves as the polarization direction of electromagnetic wave.
10. The spatial direction of electric field vector is not always fixed.the D/U ratio (the ratio of strength of useful signal to that of interference signal). • If the endpoint trace of electric field vector forms a circle. • Electrical down tilt: you adjust the electrical down tilt by adjusting the phase of oscillators.3.5:1 at most. The dual polarization antenna in LTE networks usually use ±45° cross polarization mode.3. The elliptical polarization usually applies for satellite communication. the polarization wave is circular polarization wave. After the preset electrical down tilt is sold out of the factory.10 VSWR (Voltage Standing Wave Ratio)
In mobile communication systems. The polarization modes of antennas include the polarization and dual polarization. The adjustable electrical down tilt is adjustable.9 Down Tilt
The down tilt of antenna is an important means that you can enhance the signal level of serving cell and reduce the interference with other cells. You can adjust the mechanical down tilt and electrical down tilt simultaneously. The dual polarization antenna reduces the impact from multi-path attenuation and improves the quality of signals received by the eNodeB by using polarization diversity. The electromagnetic wave of which the spatial direction of electric filed vector keeps fixed any time is the linear polarization wave. the VSWR of antenna is 1. With the ground as a reference. The common down tilt modes include mechanical down tilt. • If the endpoint trace of electric field vector forms an ellipse. The electromagnetic wave of different bands caters for different polarization modes for propagation. the polarization of which the direction of electric field vector is parallel to ground is the horizontal polarization wave and polarization of which the direction of electric field vector is vertical to ground is the horizontal polarization wave. The spatial direction of electric field vector is the direction of maximum radiation by antenna. The elliptical polarization wave and circular polarization wave have polarization direction. The mobile communication systems usually choose vertical polarization while the broadcasting systems usually choose horizontal polarization. the down tilt cannot be adjusted. The level of the first upper side lobe compared with main lobe shall be smaller than –18 dB.
10.

13 Input Port of Antenna
To improve the reliability of passive intermodulation and RF connection.11 Port Isolation
For multi-port antennas. the power capacity per port shall exceed 150 W (in a 65°C ambient temperature).3.
10. the reflected and incident waves form standing wave after overlapping on the feeder. As a result. The passive parts are usually considered linear but they may have non-linearity to some degree under high power due to the following factors: • The contact between different metals • The contact between the same metal with rough surface
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.5:1. the isolation must exceed 30 dB when the Rx port is the TX port. such as matching.
10. and filters work under high power of multi-carrier. balancing. If the power of a carrier is 20 W and a port of the antenna can support four carriers at most. therefore. the communication distance will be shortened and the reflected power will return the transmitter. feeders. there shall be a protective cap over the port to avoid generating oxide or absorbing impurity. the power amplifier may be burnt and the communication system will work abnormally.14 Passive Intermodulation (PIM)
The passive intermodulation is caused by non-linearity of the part when the passive parts like connectors. The antenna comprises of coupling parts. the RL is 13.
10.3.98 dB.3. If the VSWR is over large. so it can bear a limited power. the input port of antenna is 7/16 DIN-Female.
10.3. antennas. The ratio of the maximum adjacent voltage of standing wave to the minimum adjacent voltage of standing wave is the voltage standing wave ratio (VSWR).12 Power Capacity
It is the average power capacity. When the input impedance of antenna is not equal to characteristic impedance. such as dual polarization antenna and dual band dual polarization antenna. Before the antenna is used.So the reflection coefficient is calculated as below:
You can also represent the matching character of port with echo loss as below:
If the VSWR is 1. and phase shift. the maximum input power of antenna is 80 W.

there is no such restriction. In the littoral areas. the wind is strong with high speed.3. and outlook of antenna.3. In suburban and rural areas. cable. and especially the intermodulation products in the receiver band have severe impact on the receiving performance of system. weight. salt mist-proof.3.15 Dimensions and Weight of Antenna
To facilitate storage.18 Lightning Protection
A direct DC connection of each RF input ports of antenna to the ground is required. hidden.16 Wind Load
The antennas are usually installed on high buildings or towers.3. and according with technical requirements.
10.
10. For an omnidirectional antenna. and safety. so the antennas are required to work normally under a wind speed of 36 m/s and to keep complete under a wind speed of 55 m/s.• Loose connection • Rusty or water filled connection • Magnetic objects The intermodulation product interferes with communication systems. In some windy areas. small.
10. there are strict requirements on the intermodulation feature of passive parts like connectors. The antenna can usually resist strong wind. the antenna is required to have a size as small as possible and a weight as light as possible when all the electrical specifications are met. In urban areas.19 Three-proof Capability
The antenna of eNodeB must capable of damp-proof.17 Work Temperature and Humidity
The antenna of eNodeB shall work in a temperature of –40°C to +65°C and a humidity of 0 to 100%. As a result.3. installation.20 Camouflaged Antenna Scheme for Sites
A camouflaged antenna is beautiful. and beautiful. The operators have more and more strict requirements on the dimensions. it can also be installed bottom up and meet the three-proof capacity. the antenna of eNodeB shall be light.3. so you must focus on both the technical and non-technical specifications upon antenna selection. and antennas as below: • Passive intermodulation index of connects: ≤ –150 dBc • Passive intermodulation index of cable: ≤ –170 dBc • Passive intermodulation index of antenna: ≤ –150 dBc
10. the antennas are damaged due to unstable tower and pole.
10. The camouflaged antenna aims to keep consistent with the environment and to avoid being noticed so that the mobile communication project
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. so you shall choose the antennas with small surface area.
10. and leaf mold-proof. transport.

Figure 10-4 Outlook of customized camouflaged antennas
Figure 10-5 The bottom chart of antenna
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. The antenna camouflage aims to hidden it in the environment. The customized camouflaged antennas are various in shapes.3.proceeds smoothly. There are no fixed modes and methods for antenna camouflage.21 Customized Camouflage
Some vendors provide special antennas (such as cluster antenna). because the customized antenna is expensive. The camouflaged antenna applies for urban site construction and coverage solutions for top grade residence area. The following paragraphs focus on some antenna camouflage schemes. The antenna camouflage changes to flexible forms in different scenarios. as shown in figure below. The antenna camouflage includes the following types: • Customized camouflage • Outlook camouflage • Camouflage in special environment
10. The application of this camouflage is narrow. and these antennas usually include the three-side electrical tilting directional antenna. You can choose proper beautification modes according to the environment for actual installation.

22 Outlook Camouflage
For outlook camouflage. Paint the antenna with an ambient color so that the residents take it as ornament of environment. You can camouflage antennas with the previous methods. you can use the flat panel antenna. In addition. the residents reject installing antennas on the roof. you can use the following methods.10.3. and indoor areas. In communities or on streets.3. community.23 Antenna Camouflage in Special Environment
Residents are sensitive to antennas in some special scenarios. as shown in figure below
Figure 10-6 Painting camouflage
10. Especially in a community. such as part. according to the special installation position of antenna. as the advertising board and road sign shown in figure below. you need design a scheme that the installed antenna accords with the environment and residents can seldom identify the antenna.
Figure 10-7 Flat panel antennas camouflaged by advertising board and road sign
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.